Document:

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                                                                 Exhibit 10.10

                                PROMISSORY NOTE

AMOUNT:  $1,300,000 USD                 DATE:  September 30th, 2005

            FOR VALUE RECEIVED, the undersigned, Canadian Solar Inc. (the
"Debtor"), hereby acknowledges itself indebted and unconditionally promises to
pay to or to the order of ATS Automation Tooling Systems Inc. (the "Holder"),
the sum of ONE MILLION THREE HUNDRED THOUSAND DOLLARS ($1,300,000) in United
States Dollars, ON DEMAND together with interest thereon calculated
semi-annually at a rate equal to the Bank of Nova Scotia's published U.S. Dollar
Base Rate in Canada in effect from time to time, with interest on overdue
interest, as well after as before maturity, default and judgment. Interest shall
be payable semi-annually until the principal sum is fully repaid, the first such
payment to be payable on the date six months following the date of this Note.

            The Debtor hereby waives demand, presentment, protest, dishonour and
notice of dishonour in respect hereof. The failure of the Holder to exercise any
of its rights hereunder in any instance shall not constitute a waiver thereof in
that or any other instance.

            The Debtor hereby agrees to pay all costs and expenses (including
all reasonable legal costs) paid or incurred by the Holder in collecting the
principal then outstanding.

                                     Canadian Solar Inc.

                                     Per:  /s/
                                          --------------------------
                                          Duly Authorized Officer<PAGE>

                                                                  Exhibit 10.11

                             AGREEMENT OF GUARANTEE

B E T W E E N:

             XIAO HUA QU, A.K.A. SHAWN QU,

             (hereinafter called the "Guarantor"),

                                                              OF THE FIRST PART;

- and -

             ATS AUTOMATION TOOLING SYSTEMS INC.

             (hereinafter called "Lender"),

                                                             OF THE SECOND PART.

WHEREAS Canadian Solar Inc. (the "Company") has authorized the issue to the
Lender of a promissory note (the "Note") in the principal amount of One Million
Three Hundred Thousand US Dollars ($1,300,000.00); and

WHEREAS the Lender requires that the Guarantor enter into this Agreement in
order to assist the Company, for the mutual benefit of the Company and the
Guarantor.

NOW THEREFORE THIS AGREEMENT WITNESSETH that in consideration of the premises
the Guarantor covenants and agrees with the Lender as follows:

                                   ARTICLE 1
                                   GUARANTEE

1.1   The Guarantor unconditionally guarantees and covenants with the Lender
      that the Company will duly and punctually pay to the Lender the principal
      of, interest on and all other moneys owing under the Note as and when the
      same become due and payable according to the terms of the Note.

1.2   The Guarantor hereby acknowledges communication of the terms of the Note
      and consents to and approves of the same. The guarantee herein contained
      shall take effect and be binding upon the Guarantor notwithstanding any
      defect in or omission from the Note.

1.3   The liability of the Guarantor under Section 1.1 hereof shall be joint and
      several with that of the Company and shall be absolute and unconditional.
      The Guarantor shall for all purposes of the guarantee be regarded as in
      the same position as a principal debtor, and hereby expressly waives
      demand, presentment, protest and notice thereof and of default. The
      obligation of the Guarantor hereunder shall be deemed to arise in respect
      of each default. Notwithstanding the foregoing, the Lender agrees that it
      shall use all

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      commercially reasonable efforts to collect payment on the Note from the
      Company, prior to seeking recourse against Guarantor under the terms of
      this Guarantee.

                                   ARTICLE 2
                            DEFAULT AND ENFORCEMENT

2.1   If the Company shall make default in payment of the principal of, interest
      on or any other moneys owing under the Note as and when the same becomes
      due and payable, then the Guarantor shall forthwith on demand by the
      Lender pay to the Lender the principal, interest and other moneys in
      default.

2.2   If the Guarantor shall fail forthwith on demand to make good any such
      default, the Lender may in its discretion proceed with the enforcement of
      its rights hereunder and may proceed to enforce such rights or from time
      to time any thereof prior to, contemporaneously with or after any action
      taken under the Note. The Guarantor shall pay on demand all costs and
      expenses (including legal fees on a solicitor and own client basis)
      incurred by the Lender in enforcing or attempting to enforce its rights
      hereunder and all proceedings taken in relation hereto; all such costs and
      expenses and other moneys payable hereunder shall bear interest at the
      interest rate provided for in the Note.

2.3   All sums paid to or recovered by the Lender pursuant to the provisions
      hereof shall be applied by it in payment of its costs and expenses payable
      hereunder and the principal, interest and other moneys owing on the Note
      in such order as the Lender in its sole discretion may determine.

2.4   The Lender may waive any default of the Guarantor hereunder upon such
      terms and conditions as it may determine provided that no such waiver
      shall extend to or be taken in any manner whatsoever to affect any
      subsequent default or the rights resulting therefrom.

2.5   Any moneys paid by or recovered from the Guarantor hereunder shall be held
      to have been paid pro tanto in discharge of the liability of the Guarantor
      hereunder, but not in discharge of the liability of the Company, and in
      the event of any such payment by or recovery from the Guarantor, the
      Guarantor hereby assigns any rights with respect to or arising from such
      payment or recovery (including without limitation any right of
      subrogation) to the Lender unless or until the Lender has received in the
      aggregate payment in full of all moneys owing on the Note.

                                   ARTICLE 3
                             RELEASE AND DISCHARGE

3.1   The liability of the Guarantor hereunder shall not be limited, released,
      discharged or in any way affected by any release, loss or alteration in or
      dealing with the security under the Note, or by time being given to the
      Company or to any person whomsoever by the Lender or by any claim for
      negligence on the part of the Lender or any person acting as the Lender's
      agent; or by any amendment to the Note; or by any compromise, arrangement,
      composition or plan of reorganization affecting the Company or the
      security under the Note; or by release of any person liable directly or as
      surety or otherwise; or by waiver of any default under the Note, or by any
      dealings whatsoever between the Lender

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      and the Company or any other person or persons whomsoever, or by any other
      act, omission or proceedings in relation to the Note or this Agreement
      whereby the Guarantor might otherwise be released or exonerated or the
      liabilities and obligations of the Guarantor hereunder affected. Any
      claims by the Guarantor against the Lender or its agents in respect of any
      of the foregoing matters are hereby waived.

3.2   After all moneys payable by the Company under the Note have been paid in
      full, this guarantee cease and become null and void and the Lender shall,
      at the request and at the expense of the Guarantor execute and deliver a
      release to the Guarantor.

                                   ARTICLE 4
                                 MISCELLANEOUS

4.1   Any notices given hereunder shall be conclusively deemed effectively given
      if delivered personally to either of the parties at their last known
      address if forwarded by registered mail to such party at such address. Any
      notice so mailed shall be conclusively deemed given on the third business
      day after the day of mailing, provided that in the event of a known
      disruption of postal service notice shall be given by personal delivery
      only. Either party hereto may effect a change of address by written notice
      given to the other party hereto in accordance with this section.

4.2   This Agreement shall be construed in accordance with and governed by the
      laws of the Province of Ontario and shall extend to and be binding upon
      the heirs, executors, administrators and personal representatives of the
      Guarantor.

IN WITNESS WHEREOF the Guarantor has executed these presents on the       day of
September, 2005.

SIGNED, SEALED AND DELIVERED  }
     in the presence of       }
                              }
 /s/                          }         /s/
-------------------------     }        --------------------------
Witness                       }        Shawn Qu

                                       3<PAGE>

                                                                  EXHIBIT 10.12

                       GUARANTEE AND POSTPONEMENT OF CLAIM

TO: ROYAL BANK OF CANADA

     FOR VALUABLE CONSIDERATION, receipt whereof is hereby acknowledged, the
undersigned and each of them (if more than one) hereby jointly and severally
guarantee(s) payment on demand to Royal Bank of Canada (hereinafter called the
"Bank") of all debts and liabilities, present or future, direct or indirect,
absolute or contingent, matured or not, at any time owing by Canadian Solar Inc.
(hereinafter called the "customer") to the Bank or remaining unpaid by the
customer to the Bank, heretofore or hereafter incurred or arising and whether
incurred by or arising from agreement or dealings between the Bank and the
customer or by or from any agreement or dealings with any third party by which
the Bank may be or become in any manner whatsoever a creator of the customer or
however otherwise incurred or arising anywhere within or outside the country
where this guarantee is executed and whether the customer be bound alone or with
another or others and whether as principal or surety (such debts and liabilities
being hereinafter called the "liabilities"); the liability of the undersigned
hereunder being limited to the sum of $500,000.00 Five Hundred Thousand Dollars
together with interest thereon from the date of demand for payment at a rate
equal to the Bank's Prime interest Rate per annum in effect from time to time
plus 1.550 One AND Fifty-Five One Hundredths percent per annum as well after as
before default and judgment.

AND THE UNDERSIGNED AND EACH OF THEM (IF MORE THAN ONE) HEREBY JOINTLY AND
SEVERALLY AGREE(S) WITH THE BANK AS FOLLOWS:

(1) The Bank may grant time, renewals, extensions, indulgences, releases and
discharges to, take securities (which word as used herein includes securities
taken by the Bank from the Customer and others, monies which the Customer has on
deposit with the Bank, other assets of the Customer held by the Bank in
safekeeping or otherwise, and other guarantees) from and give the same and any
or all existing securities up to, abstain from taking securities from, or
perfecting securities of, cease or refrain from giving credit or making loans or
advances to, or change any term or condition applicable to the liabilities,
including without limitation, the rate of interest or maturity date, if any, or
introduce new terms and conditions with regard to the liabilities, or accept
compositions from and otherwise deal with, the customer and others and with all
securities as the Bank may see fit, and may apply all moneys at any time
received from the customer or others or from securities upon such part of the
liabilities as the Bank deems best and change any such application in whole or
in part from time to time as the Bank may see fit, the whole without in any way
limiting or lessening the liability of the undersigned under this guarantee, and
no loss of or in respect of any securities received by the Bank from the
customer or others, whether occasioned by the fault of the Bank or otherwise,
shall in any way limit or lessen the liability of the undersigned under this
guarantee.

(2) This guarantee shall be a continuing guarantee and shall cover all the
liabilities, and it shall apply to and secure any ultimate balance due or
remaining unpaid to the Bank.

(3) The Bank shall not be bound to exhaust its recourse against the customer or
others or any securities it may at any time hold before being entitled to
payment from the undersigned of the liabilities. The undersigned renounce(s) to
all benefits of discussion and division.

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(4) The undersigned or any of them may, by notice in writing delivered to the
Manager of the branch or agency of the Bank receiving this instrument, with
effect from and after the date that is 30 days following the date of receipt by
the Bank of such notice, determine their or his/her liability under this
guarantee in respect of liabilities thereafter incurred or arising but not in
respect of any liabilities theretofore incurred or arising even though not then
matured, provided, however, that notwithstanding receipt of any such notice the
Bank may fulfill any requirements of the customer based on agreements express or
implied made prior to the receipt of such notice and any resulting liabilities
shall be covered by this guarantee; and provided further that in the event of
the determination of this guarantee as to one or more of the undersigned it
shall remain a continuing guarantee as to the other or others of the
undersigned.

(5) All indebtedness and liability, present and future, of the customer to the
undersigned or any of them are hereby assigned to the Bank and postponed to the
liabilities, and all moneys received by the undersigned or any of them in
respect thereof shall be received in trust for the Bank and forthwith upon
receipt shall be paid over to the Bank, the whole without in any way limiting or
lessening the liability of the undersigned under the foregoing guarantee; and
this assignment and postponement is independent of the said guarantee and shall
remain in full effect notwithstanding that the liability of the undersigned or
any of them under the said guarantee may be extinct. The term "Liabilities", as
previously defined, for purposes of the postponement feature provided by this
agreement and this section in particular, includes any funds advanced or held at
the disposal of the customer under any line(s) of credit.

(6) This guarantee and agreement shall not be affected by the death or lass or
diminution of capacity of the undersigned or any of them or by any change in the
name of the customer or in the membership of the customer's firm through the
death or retirement of one or more partners or the introduction of one or more
other partners or otherwise, or by the acquisition of the customer's business by
a corporation, or by any change whatsoever in the objects, capital structure or
constitution of the customer, or by the customer's business being amalgamated
with a corporation, but shall notwithstanding the happening of any such event
continue to apply to all the liabilities whether theretofore or thereafter
incurred or arising and in this instrument the word "customer" shall Include
every such firm and corporation.

(7) This guarantee shall not be considered as wholly or partially satisfied by
the payment or liquidation at any time or times of any sum or sums of money for
the time being due or remaining unpaid to the Bank, and all dividends,
compositions, proceeds of security valued and payments received by the Bank from
the customer or from others or from estates shall be regarded for all purposes
as payments in gross without arty right on the part of the undersigned to claim
in reduction of the liability under this guarantee the benefit of any such
dividends, compositions, proceeds or payments or any securities held by the Bank
or proceeds thereof, and the undersigned shall have no right to be subrogated in
any rights of the Bank until the Bank shall have received payment in full of the
liabilities.

(8) All monies, advances, renewals, credits and credit facilities in fact
borrowed or obtained from the Bank shall be deemed to form part of the
liabilities, notwithstanding any lack or limitation of status or of power,
incapacity or disability of the customer or of the directors, partners or agents
of the customer, or that the customer may not be a legal or suable entity, or
any irregularity, defect or informality in the borrowing or obtaining of such
monies, advances,

                                        2

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renewals, credits or credit facilities, or any other reason, similar or not, the
whole whether known to the Bank or not. Any sum which may not be recoverable
from the undersigned on the footing of a guarantee, whether for the reasons set
out in the previous sentence, or for any other reason, similar or not, shall be
recoverable from the undersigned and each of them as sole or principal debtor in
respect of that sum, and shall be paid to the Bank on demand with interest and
accessories.

(9) This guarantee is in addition to and not in substitution for any other
guarantee, by whomsoever given, at any time held by the Bank, arid any present
or future obligation to the Bank incurred or arising otherwise than under a
guarantee, of the undersigned or any of them or of any other obligant, whether
bound with or apart from the customer; excepting any guarantee surrendered for
cancellation on delivery of this instrument.

(10) The undersigned and each of them shall be bound by any account settled
between the Bank and the customer, and if no such account has been so settled
immediately before demand for payment under this guarantee any account stated by
the Bank shall be accepted by the undersigned and each of them as conclusive
evidence of the amount which at the date of the account so stated is due by the
customer to the Bank or remains unpaid by the customer to the Bank.

(11) This guarantee and agreement shall be operative and binding upon every
signatory thereof notwithstanding the non-execution thereof by any other
proposed signatory or signatories, and possession of this instrument by the Bank
shall be conclusive evidence against the undersigned and each of them that this
instrument was not delivered in escrow or pursuant to any agreement that it
should not be effective until any conditions precedent or subsequent had been
complied with, unless at the time of receipt of this instrument by the Bank each
signatory thereof obtains from the Manager of the branch or agency of the Bank
receiving this instrument a letter setting out the terms and conditions under
which this instrument was delivered and the conditions, if any, to be observed
before it becomes effective.

(12) No suit based on this guarantee shall be instituted until demand for
payment has been made, and demand for payment shall be deemed to have been
effectually made upon any guarantor if and when an envelope containing such
demand, addressed to such guarantor at the address of such guarantor last known
to the Bank, is posted, postage prepaid, in the post office, and in the event of
the death of any guarantor demand for payment addressed to any of such
guarantor's heirs, executors, administrators or legal representatives at the
address of the addressee last known to the Bank and posted as aforesaid shall be
deemed to have been effectually made upon all of them. Moreover, when demand for
payment has been made, the undersigned shall also be liable to the Bank for all
legal costs (on a solicitor and own client basis) incurred by or on behalf of
the Bank resulting from any action instituted on the basis of this guarantee.
All payments hereunder shall be made to the Bank at a branch or agency of the
Bank.

(13) This instrument covers all agreements between the parties hereto relative
to this guarantee and assignment end postponement, and none of the parties shall
be bound by any representation or promise made by any person relative thereto
which is not embodied herein.

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(14) This guarantee and agreement shall extend to and enure to the benefit of
the Bank and its successors and assigns, and every reference herein to the
undersigned or to each of them or to any of them, is a reference to and shall be
construed as including the undersigned and the heirs, executors, administrators,
legal representatives, successors and assigns of the undersigned or of each of
them or of any of them, as the case may be, to and upon all of whom this
guarantee and agreement shall extend and be binding.

(15) Prime interest Rate is the annual rate of interest announced from time to
time by Royal Bank of Canada as a reference rate then in effect for determining
interest rates on Canadian dollar commercial loans in Canada.

(16) This Guarantee and Postponement of Claim shall be governed by and construed
in accordance with the laws of the Province of Ontario ("Jurisdiction"). The
undersigned irrevocably submits to the courts of the Jurisdiction in any action
or proceeding arising out of or relating to this Guarantee and Postponement of
Claim, and irrevocably agrees that all such actions and proceedings may be heard
and determined in such courts, and irrevocably waives, to the fullest extent
possible, the defense of an inconvenient forum. The undersigned agrees that a
judgment or order in any such action or proceeding may be enforced in other
jurisdictions in any manner provided by law. Provided, however, that the Bank
may serve legal process in any manner permitted by law or may bring an action or
proceeding against the undersigned or the property or assets of the undersigned
in the courts of any other jurisdiction.

(17) The Undersigned hereby acknowledges receipt of a copy of this agreement.

(18) The Undersigned hereby waives Undersigned's right to receive a copy of any
Financing Statement or Financing Change Statement registered by the Bank.

GIVEN UNDER SEAL at Toronto this
                                 -----------------------------------------------
                                      [MONTH]          [DAY]          [YEAR]

SIGNED, SEALED AND DELIVERED IN THE PRESENCE OF

/s/                                     /s/                               (SEAL)
-------------------------------------   ----------------------------------
Witness                                 XIAOHUA QU
                                        PRESIDENT

                                                                          (SEAL)
-------------------------------------   ----------------------------------
Witness

                                                                          (SEAL)
-------------------------------------   ----------------------------------
Witness

                                                                          (SEAL)
-------------------------------------   ----------------------------------
Witness

                                        4

<PAGE>

(To be completed when the guarantee is stated to be governed by the laws of the
Province of Alberta, the loan is repayable in Alberta, the guarantee is executed
in Alberta, the customer carries on business in Alberta, or the Guarantor is
resident or owns assets in Alberta.)

                  THE GUARANTEES ACKNOWLEDGEMENT ACT, (ALBERTA)
                          CERTIFICATE OF NOTARY PUBLIC

     I HEREBY CERTIFY THAT:

     (1) _________________________________________________ of ____________ in
the Province of Ontario, the Guarantor in the guarantee dated _____________ made
between ROYAL BANK OF CANADA and ________________________________________, which
this certificate is attached to or noted upon, appeared in person before me and
acknowledged that he/she had executed the guarantee;

     (2) I satisfied myself by examination of the Guarantor that he/she is aware
of the contents of the guarantee and understands it.

Given at _______________________ this _________ under my hand and seal of office

     (SEAL OF NOTARY PUBLIC)

                                        ----------------------------------------
                                        A NOTARY PUBLIC IN AND FOR

                                        ----------------------------------------

                             STATEMENT OF GUARANTOR

I am the person named in the certificate /s/
                                         ---------------------------------------
                                         Signature of Guarantor

                                        5

<PAGE>

   (To be completed when the guarantee is stated to be governed by the laws of
    the Province of Saskatchewan and the Borrower or Guarantor is a farmer in
   Saskatchewan, or the farmer or Guarantor owns farm assets in Saskatchewan.)

                       THE SASKATCHEWAN FARM SECURITY ACT
                          ACKNOWLEDGEMENT OF GUARANTEE
                                  (SECTION 31)
                     CERTIFICATE OF LAWYER OR NOTARY PUBLIC

     I HEREBY CERTIFY THAT:

     (1) _________________________________________________ of ____________ in
the Province of Ontario, the Guarantor in the guarantee dated _____________ made
between ROYAL BANK OF CANADA and ________________________________________, which
this certificate is attached to or noted upon, appeared in person before me and
acknowledged that he/she had executed the guarantee;

     (2) I satisfied myself by examination of the Guarantor that he/she is aware
of the contents of the guarantee and understands it.

     (3) I have not prepared any documents on behalf of the creditor, Royal Bank
of Canada, relating to the transaction and I am not otherwise interested in the
transaction;

     (4) I acknowledge that the Guarantor signed the following "Statement of
Guarantor" in my presence. Given at ______________ this ______________ under my
hand and seal of office

(SEAL REQUIRED WHERE NOTARY
PUBLIC SIGNS CERTIFICATE)               ----------------------------------------
                                        A LAWYER OR A NOTARY PUBLIC IN AND FOR

                                        ----------------------------------------

                             STATEMENT OF GUARANTOR

I am the person named in the certificate /s/
                                         ---------------------------------------
                                         Signature of Guarantor

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