Exhibit 10.8

SECURED PROMISSORY NOTE

(Revolving Note)



|             |  |                   
|------------ |  | ------------------
|$100,000,000 |  | April 30, 2010    
|             |  | Irvine, California

FOR VALUE RECEIVED, KBSII
350 PLUMERIA, LLC, a Delaware limited liability company, KBSII MOUNTAIN VIEW, LLC, a Delaware limited liability company, KBSII ONE MAIN PLACE, LLC, a Delaware limited liability company and KBSII PIERRE LACLEDE CENTER, LLC, a
Delaware limited liability company (Borrowers), HEREBY PROMISE TO PAY to the order of WELLS FARGO BANK, NATIONAL ASSOCIATION (Lender) the principal sum of One Hundred Million Dollars ($100,000,000), or if
less, the aggregate unpaid principal amount of all disbursements disbursed by Lender pursuant to the requirements set forth in the Loan Agreement dated as of April 30, 2010 (as amended, supplemented or restated from time to time the
Loan Agreement), among Borrowers, Lender, certain other Lenders named therein or made parties thereto and Wells Fargo Bank, National Association, as Administrative Agent, together with interest on the unpaid principal balance
hereof at the rate (or rates) determined in accordance with Section 2.7 of the Loan Agreement from the date such principal is advanced until it is paid in full. It is contemplated that there will be advances and payments under this Note
from time to time, but no advances or payments under this Note (including payment in full of the unpaid balance of principal hereof prior to maturity) shall affect or impair the validity or enforceability of this Note as to future advances
hereunder.

This Note is one of the Notes referred to in and governed by the Loan Agreement, which Loan Agreement, among other things,
contains provisions for the acceleration of the maturity hereof and for the payment of certain additional sums to Lender upon the happening of certain stated events. Capitalized terms used in this Note without definition have the same meanings as in
the Loan Agreement.

The principal amount of this Note, unless accelerated in accordance with Loan Agreement as described below, if not
sooner paid, will be due and payable, together with all accrued and unpaid interest and other amounts due and unpaid under the Loan Agreement, on the Maturity Date.

This Note is secured by, among other things, the Security Documents referred to in the Loan Agreement.

Borrowers may from time to time during the term of this Note borrow, partially or wholly repay its outstanding borrowings, and reborrow, subject to
all of the limitations, terms and conditions of this Note, the Loan Agreement and of any other agreement executed in connection with this Note, provided that the outstanding principal balance of this Note shall at no time exceed the principal amount
stated above. The unpaid principal balance of this obligation at any time shall be the total amounts advanced hereunder by the holder hereof less the amount of principal payments made hereon by or for Borrowers, which principal balance may be
endorsed hereon from time to time by the holder.

Interest on the Loans is accrued and payable in arrears on the first Business Day of
each month during the term of the Loan Agreement, commencing with the first Business Day of the first calendar month to begin after the date of this Note. Interest will be computed on the basis of the actual number of days elapsed in the period
during which interest accrues and a year of three hundred sixty (360) days. The Loan Agreement provides for the payment by Borrower of various other charges and fees, in addition to the interest charges described in the Loan Agreement, as set
forth more fully in the Loan Agreement.

All payments of any amount becoming due under this Note shall be made in the manner provided in
the Loan Agreement, in Dollars.

Upon and after the occurrence of a Default, unless such Default is waived as provided in the Loan
Agreement, this Note may, at the option of Requisite Lenders and without further demand, notice or legal process of any kind, be declared by Administrative Agent, and in such case immediately shall become, due and payable. Upon and after the
occurrence of certain Defaults, this Note shall, without any



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action by Lenders and without demand, notice or legal process of any kind, automatically and immediately become due and payable.

Demand, presentment, protest and notice of nonpayment and protest, notice of intention to accelerate maturity, notice of acceleration of maturity
and notice of dishonor are hereby waived by Borrowers. Subject to the terms of the Loan Agreement, Lender may extend the time of payment of this Note, postpone the enforcement hereof, grant any indulgences, release any party primarily or secondarily
liable hereon or agree to any subordination of Borrowers obligations hereunder without affecting or diminishing Lenders right of recourse against Borrowers, which right is hereby expressly reserved.

This Note has been delivered and accepted at Irvine, California. This Note shall be interpreted in accordance with, and the rights and liabilities
of the parties hereto shall be determined and governed by, the laws of the State of California.

All notices or other communications
required or permitted to be given pursuant to this Note shall be given to the Borrowers, Administrative Agent or Lenders at the address and in the manner provided for in the Loan Agreement.

In no contingency or event whatsoever shall interest charged in respect of the Loan evidenced hereby, however such interest may be characterized or
computed, exceed the highest rate permissible under any law that a court of competent jurisdiction shall, in a final determination, deem applicable hereto. If such a court determines that Lenders have received interest hereunder in excess of the
highest rate applicable hereto, Lenders shall, at Administrative Agents election, either (a) promptly refund such excess interest to Borrowers or (b) credit such excess to the principal balance hereof. This provision shall control
over every other provision of all agreements between Borrowers, Administrative Agent and Lenders.

Whenever possible each provision of
this Note shall be interpreted in such manner as to be effective and valid under applicable law, but if any provision of this Note shall be prohibited by or invalid under applicable law, such provision shall be ineffective to the extent of such
prohibition or invalidity, without invalidating the remainder of such provision or the remaining provisions of this Note.

The
limitations on personal liability of the shareholders, partners and members of Borrowers contained in Section 13.27 of the Loan Agreement shall apply to this Note.

[Signatures Follow on Next Page]



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IN WITNESS WHEREOF, this Note has been executed as of the date first set forth above.



|                                                              |  |                                                       |  |                                                       |  |                                                 |  |                                            |  |                               |  |  |  | 
|------------------------------------------------------------- |  | ----------------------------------------------------- |  | ----------------------------------------------------- |  | ----------------------------------------------- |  | ------------------------------------------ |  | ----------------------------- |  |  |  | 
|BORROWER                                                    |  |                                                       |  |                                                      
|                                                              |  |                                                      
|KBSII 350 PLUMERIA, LLC, a
Delaware limited liability company |  |                                                       |  |                                                      
|                                                              |  |                                                       | 
|By:                                                           |  | KBSII REIT ACQUISITION IV, LLC,                       |  |                                                       |  |                                                
|                                                              |  | a Delaware limited liability company,
its sole member |  |                                                       |  |                                                
|                                                              |  |                                                       |  |                                                      
|                                                              |  | By:                                                   |  | KBS REIT PROPERTIES II, LLC,                          |  |                                                 |  |                                           
|                                                              |  |                                                       |  | a Delaware limited liability company,
its sole member |  |                                                 |  |                                           
|                                                              |  |                                                       |  |                                                       | 
|                                                              |  |                                                       |  | By:                                                   |  | KBS LIMITED PARTNERSHIP II,                     |  |                                            |  |                              
|                                                              |  |                                                       |  |                                                       |  | a Delaware limited partnership, its
sole member |  |                                            |  |                              
|                                                              |  |                                                       |  |                                                       | 
|                                                              |  |                                                       |  |                                                       |  | By:                                             |  | KBS REAL ESTATE INVESTMENT TRUST II, INC., |  |                              
|                                                              |  |                                                       |  |                                                       |  |                                                 |  | a Maryland corporation, general
partner    |  |                               |  | 
|                                                              |  |                                                       |  |                                                       |  |                                                 | 
|                                                              |  |                                                       |  |                                                       |  |                                                 |  | By:                                        |  | /s/ Charles J. Schreiber, Jr. |  |  |  | 
|                                                              |  |                                                       |  |                                                       |  |                                                 |  |                                            |  | Charles J. Schreiber, Jr.     |  |  |  | 
|                                                              |  |                                                       |  |                                                       |  |                                                 |  |                                            |  | Chief Executive Officer       |  |  |  | 

[Signatures Continue on Next Page]



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|                                                                       |  |                                                       |  |                                                       |  |                                                 |  |                                            |  |                               |  |  |  | 
|---------------------------------------------------------------------- |  | ----------------------------------------------------- |  | ----------------------------------------------------- |  | ----------------------------------------------- |  | ------------------------------------------ |  | ----------------------------- |  |  |  | 
|BORROWER                                                             |  |                                                       |  |                                                      
|                                                                       |  |                                                      
|KBSII PIERRE LACLEDE CENTER, LLC,
a Delaware limited liability company |  |                                                       |  |                                                      
|                                                                       |  |                                                       | 
|By:                                                                    |  | KBSII REIT ACQUISITION VI, LLC,                       |  |                                                       |  |                                                
|                                                                       |  | a Delaware limited liability company,
its sole member |  |                                                       |  |                                                
|                                                                       |  |                                                       |  |                                                      
|                                                                       |  | By:                                                   |  | KBS REIT PROPERTIES II, LLC,                          |  |                                                 |  |                                           
|                                                                       |  |                                                       |  | a Delaware limited liability company,
its sole member |  |                                                 |  |                                           
|                                                                       |  |                                                       |  |                                                       | 
|                                                                       |  |                                                       |  | By:                                                   |  | KBS LIMITED PARTNERSHIP II,                     |  |                                            |  |                              
|                                                                       |  |                                                       |  |                                                       |  | a Delaware limited partnership, its
sole member |  |                                            |  |                              
|                                                                       |  |                                                       |  |                                                       | 
|                                                                       |  |                                                       |  |                                                       |  | By:                                             |  | KBS REAL ESTATE INVESTMENT TRUST II, INC., |  |                              
|                                                                       |  |                                                       |  |                                                       |  |                                                 |  | a Maryland corporation, general
partner    |  |                               |  | 
|                                                                       |  |                                                       |  |                                                       |  |                                                 | 
|                                                                       |  |                                                       |  |                                                       |  |                                                 |  | By:                                        |  | /s/ Charles J. Schreiber, Jr. |  |  |  | 
|                                                                       |  |                                                       |  |                                                       |  |                                                 |  |                                            |  | Charles J. Schreiber, Jr.     |  |  |  | 
|                                                                       |  |                                                       |  |                                                       |  |                                                 |  |                                            |  | Chief Executive Officer       |  |  |  | 

[Signatures Continue on Next Page]



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|                                                               |  |                                                       |  |                                                       |  |                                                 |  |                                            |  |                               |  |  |  | 
|-------------------------------------------------------------- |  | ----------------------------------------------------- |  | ----------------------------------------------------- |  | ----------------------------------------------- |  | ------------------------------------------ |  | ----------------------------- |  |  |  | 
|BORROWER                                                     |  |                                                       |  |                                                      
|                                                               |  |                                                      
|KBSII MOUNTAIN VIEW, LLC,
a Delaware limited liability company |  |                                                       |  |                                                      
|                                                               |  |                                                       | 
|By:                                                            |  | KBSII REIT ACQUISITION III, LLC,                      |  |                                                       |  |                                                
|                                                               |  | a Delaware limited liability company,
its sole member |  |                                                       |  |                                                
|                                                               |  |                                                       |  |                                                      
|                                                               |  | By:                                                   |  | KBS REIT PROPERTIES II, LLC,                          |  |                                                 |  |                                           
|                                                               |  |                                                       |  | a Delaware limited liability company,
its sole member |  |                                                 |  |                                           
|                                                               |  |                                                       |  |                                                       | 
|                                                               |  |                                                       |  | By:                                                   |  | KBS LIMITED PARTNERSHIP II,                     |  |                                            |  |                              
|                                                               |  |                                                       |  |                                                       |  | a Delaware limited partnership, its
sole member |  |                                            |  |                              
|                                                               |  |                                                       |  |                                                       | 
|                                                               |  |                                                       |  |                                                       |  | By:                                             |  | KBS REAL ESTATE INVESTMENT TRUST II, INC., |  |                              
|                                                               |  |                                                       |  |                                                       |  |                                                 |  | a Maryland corporation, general
partner    |  |                               |  | 
|                                                               |  |                                                       |  |                                                       |  |                                                 | 
|                                                               |  |                                                       |  |                                                       |  |                                                 |  | By:                                        |  | /s/ Charles J. Schreiber, Jr. |  |  |  | 
|                                                               |  |                                                       |  |                                                       |  |                                                 |  |                                            |  | Charles J. Schreiber, Jr.     |  |  |  | 
|                                                               |  |                                                       |  |                                                       |  |                                                 |  |                                            |  | Chief Executive Officer       |  |  |  | 

[Signatures Continue on Next Page]



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|                                                                |  |                                                       |  |                                                       |  |                                                 |  |                                            |  |                               |  |  |  | 
|--------------------------------------------------------------- |  | ----------------------------------------------------- |  | ----------------------------------------------------- |  | ----------------------------------------------- |  | ------------------------------------------ |  | ----------------------------- |  |  |  | 
|BORROWER                                                      |  |                                                       |  |                                                      
|                                                                |  |                                                      
|KBSII ONE MAIN PLACE, LLC,
a Delaware limited liability company |  |                                                       |  |                                                      
|                                                                |  |                                                       | 
|By:                                                             |  | KBSII REIT ACQUISITION VII, LLC,                      |  |                                                       |  |                                                
|                                                                |  | a Delaware limited liability company,
its sole member |  |                                                       |  |                                                
|                                                                |  |                                                       |  |                                                      
|                                                                |  | By:                                                   |  | KBS REIT PROPERTIES II, LLC,                          |  |                                                 |  |                                           
|                                                                |  |                                                       |  | a Delaware limited liability company,
its sole member |  |                                                 |  |                                           
|                                                                |  |                                                       |  |                                                       | 
|                                                                |  |                                                       |  | By:                                                   |  | KBS LIMITED PARTNERSHIP II,                     |  |                                            |  |                              
|                                                                |  |                                                       |  |                                                       |  | a Delaware limited partnership, its
sole member |  |                                            |  |                              
|                                                                |  |                                                       |  |                                                       | 
|                                                                |  |                                                       |  |                                                       |  | By:                                             |  | KBS REAL ESTATE INVESTMENT TRUST II, INC., |  |                              
|                                                                |  |                                                       |  |                                                       |  |                                                 |  | a Maryland corporation, general
partner    |  |                               |  | 
|                                                                |  |                                                       |  |                                                       |  |                                                 | 
|                                                                |  |                                                       |  |                                                       |  |                                                 |  | By:                                        |  | /s/ Charles J. Schreiber, Jr. |  |  |  | 
|                                                                |  |                                                       |  |                                                       |  |                                                 |  |                                            |  | Charles J. Schreiber, Jr.     |  |  |  | 
|                                                                |  |                                                       |  |                                                       |  |                                                 |  |                                            |  | Chief Executive Officer       |  |  |  |