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                                 November 4, 1998


Larry Tannenbaum
1700 Santa Cruz Ave.
Menlo Park, CA 94025

Dear Larry:

     On behalf of LJL BioSystems, Inc. (the "COMPANY"), I am pleased to offer
you the position of Sr. Vice President and Chief Financial Officer.  Speaking
for myself, as well as the other members of the Company's management team, we
are all very impressed with your credentials and we look forward to your future
success in this position.

     The terms of your new position with the Company are as set forth below:

     1.   POSITION.

          a.  You will become Sr. Vice President and the Chief Financial Officer
(CFO) of the Company, working out of the Company's headquarters office in
Sunnyvale, California.  As CFO you will have overall responsibility for finance,
administration, investor relations, as well as being a participant in business
development.  You will report to the Company's Chief Executive Officer.

          b.  You agree to the best of your ability and experience that you will
at all times loyally and conscientiously perform all of the duties and
obligations required of and from you pursuant to the express and implicit terms
hereof, and to the reasonable satisfaction of the Company. During the term of
your employment, you further agree that you will devote all of your business
time and attention to the business of the Company, the Company will be entitled
to all of the benefits and profits arising from or incident to all such work
services and advice, you will not render commercial or professional services of
any nature to any person or organization, whether or not for compensation,
without the prior written consent of the Company's Board of Directors, and you
will not directly or indirectly engage or participate in any business that is
competitive in any manner with the business of the Company.  Nothing in this
letter agreement will prevent you from accepting speaking or presentation
engagements in exchange for honoraria or from serving on boards of charitable
organizations, or from owning no more than one percent (1%) of the outstanding
equity securities of a corporation whose stock is listed on a national stock
exchange.

     2.   START DATE.  Subject to fulfillment of any conditions imposed by this
letter agreement, you will commence this new position with the Company on or
before November 9, 1998 (which date of employment shall be your "START DATE").

     3.   PROOF OF RIGHT TO WORK.  For purposes of federal immigration law, you
will be required to provide to the Company documentary evidence of your identity
and eligibility for employment in the United States.  Such documentation must be
provided to us within three (3) business days of your Start Date, or our
employment relationship with you may be terminated.

     4.   COMPENSATION.

          a.   BASE SALARY.  You will be paid a monthly salary of $15,833.33,
which is equivalent to $190,000.00 on an annualized basis.  Your salary will be
payable pursuant to the Company's regular payroll policy (or in the same manner
as other officers of the Company).

          b.   ANNUAL REVIEW.  Your base salary will be reviewed at the end of
each calendar year as part of the Company's normal salary review process.

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     5.   STOCK OPTIONS.

          a.   INITIAL GRANT.  In connection with the commencement of your
employment, the Company will recommend that the Board of Directors grant you an
option to purchase 100,000 shares of the Company's Common Stock ("INITIAL GRANT
SHARES") ") at the market price on the date of grant.  The Initial Grant Shares
will vest at the following rate:  20% of the total Initial Grant Shares shall
vest on the first annual anniversary of the vesting commencement date (your
Start Date) and 1/20th of the total Initial Grant Shares shall vest on the
quarterly anniversary of the vesting commencement date thereafter.  Vesting
will, of course, depend on your continued employment with the Company. The
option will be an incentive stock option subject to the terms of the Company's
1997 Stock Plan and the Stock Option Agreement between you and the Company and
limits under the tax code.

          b.   BONUS OPTION.  In connection with the commencement of your
employment, the Company will recommend that the Board of Directors grant you an
additional option to purchase 40,000 shares of the Company's Common Stock
("BONUS SHARES") at the market price on the date of grant. The Bonus Shares will
vest on the five year anniversary of the vesting commencement date (your Start
Date), PROVIDED THAT if you meet certain performance milestones (to be mutually
agreed on between the CEO and you) during your first twelve months of
employment, up to 20% of the Bonus Shares shall vest on the annual anniversary
of the vesting commencement date, and PROVIDED FURTHER that if you meet certain
performance milestones (to be mutually agreed on between the Chief Executive
Officer and you each subsequent 12 month period of employment) during each
subsequent twelve month period of employment, up to an additional 20% of the
Bonus Shares shall vest on each such subsequent annual anniversary of the
vesting commencement date, such that if the performance milestones for each year
are fully met, the option to purchase Bonus Shares shall vest at an accelerated
rate of 20% per annum on each annual anniversary of the vesting commencement
date (full vesting in five years). Vesting will, of course, depend on your
continued employment with the Company. The option will be an incentive stock
option subject to the terms of the Company's 1997 Stock Plan and the Stock
Option Agreement between you and the Company and limits under the tax code.

          c.   SPECIAL BONUS OPTION. In connection with the commencement of your
employment, the Company will recommend that the Board of Directors grant you a
special bonus option to purchase 20,000 shares of the Company's Common Stock
("Special Bonus Shares") at the market price on the date of grant. The Special
Bonus Shares will vest on the five year anniversary of the vesting commencement
date (your Start Date), provided that if you close the Company's next rounds of
equity or debt financing (not including lease lines, lines of credit, and the
like) in excess of $15 million during your first eighteen months of employment
(or such other performance milestone as mutually agreed on by the Chief
Executive Officer and you), up to 100% of the Special Bonus Shares shall vest on
the annual anniversary of the vesting commencement date.  The option will be an
incentive stock option subject to the terms of the Company's 1997 Stock Plan and
the Stock Option Agreement between you and the Company and limits under the tax
code.
          d.   SUBSEQUENT OPTION GRANTS.  Subject to the discretion of the
Company's Board of Directors, you may be eligible to receive additional grants
of stock options or purchase rights from time to time in the future, on such
terms and subject to such conditions as the Board of Directors shall determine
as of the date of any such grant.

     6.   BENEFITS.

          a.   INSURANCE BENEFITS.  The Company will provide you with its
standard medical and dental insurance benefits, beginning on the first day of
the month after the month in which your employment commences, with 100% of the
premium paid by the Company. Dependent coverage will be offered at extra cost
and partially paid for by you on a pretax basis. Long term disability insurance
is included in the benefits package and is paid for by the Company. After you
have been employed for three months with the Company, you will be eligible to
participate in the Company's 401k retirement plan offered through Prudential
Securities.  In addition, the Company currently indemnifies all officers and
directors to the maximum extent permitted by law, and you will be requested to
enter into the Company's standard form of Indemnification Agreement giving you
such protection.  Pursuant to the Indemnification Agreement, the Company will
agree to advance any expenses for which indemnification is available to the
extent allowed by applicable law.

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          b.   VACATION.  You will be entitled to 10 days paid vacation per
year, pro-rated for the remainder of this calendar year, and one additional week
of unpaid vacation.  After three years of employment with the Company, you will
be entitled to 15 days paid vacation per year.  After seven years of employment
with the Company, you will be entitled to 20 days paid vacation per year.

     7.   PROPRIETARY INFORMATION AND INVENTIONS AGREEMENT.  Your acceptance of
this offer and commencement of employment with the Company is contingent upon
the execution, and delivery to an officer of the Company, of the Company's
Proprietary Information and Inventions Agreement prior to or on your Start Date.

     8.   AT-WILL EMPLOYMENT.  Notwithstanding the Company's obligation
described in Section 9 below, your employment with the Company will be on an "at
will" basis, meaning that either you or the Company may terminate your
employment at any time for any reason or no reason, without further obligation
or liability.

     9.   SEVERANCE AGREEMENT.  If your employment is terminated by any
successor-in-interest to the Company for any reason other than cause within
three (3) years after your Start Date, as determined by the Company's Board of
Directors, (i) you will be entitled to receive continuation of your base salary
for up to six months following the date of termination of your employment
(the"SEVERANCE PERIOD"), PROVIDED THAT if you commence full-time employment
during the Severance Period, the Company's obligation to pay any severance shall
cease at the time of such employment, and (ii) 100% of your unvested outstanding
Initial Grant Shares shall immediately vest in full.  For purposes of this
section, "full-time employment" shall be defined as at least 35 hours per week
of compensated labor, including, but not limited to, consulting or other
contract work.

     We are all delighted to be able to extend you this offer and look forward
to working with you.  To indicate your acceptance of the Company's offer, please
sign and date this letter in the space provided below and return it to me, along
with a signed and dated copy of the Proprietary Information and Inventions
Agreement.  This letter and Proprietary Information and Inventions Agreement set
forth the terms of your employment with the Company and supersede any prior
representations or agreements, whether written or oral.  This letter may not be
modified or amended except by a written agreement, signed by the Company and by
you.  This offer shall expire at 12 noon on November 7, 1998 if you have not
delivered an acceptance to the Company before then.


                                     Very truly yours,

                                     LJL BIOSYSTEMS, INC.

                                     By:      /s/ Lev J. Leytes
                                             -----------------------------------

                                     Title:  President & Chief Executive Officer
                                             -----------------------------------

ACCEPTED AND AGREED:

Larry Tannenbaum

  /s/ Larry Tannenbaum
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Signature

     November 7, 1998
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Date