Exhibit 31.2


Certification of Principal  Accounting  Officer pursuant to Securities  Exchange
Act Rules  13a-14(a)  and  15d-14(a)  as adopted  pursuant to Section 302 of the
Sarbanes Oxley Act of 2002.


I, Francis Chang, certify that:

1.       I have reviewed this annual report on Form 10-KSB of Electronic  Sensor
         Technology, Inc.;

2.       Based on my  knowledge,  this annual report does not contain any untrue
         statement of a material fact or omit to state a material fact necessary
         to make the statements made, in light of the circumstances  under which
         such  statements  were made, not misleading  with respect to the period
         covered by this annual report;

3.       Based on my knowledge,  the financial  statements,  and other financial
         information  included  in this  annual  report,  fairly  present in all
         material  respects the financial  condition,  results of operations and
         cash flows of the small  business  issuer as of, and for,  the  periods
         presented in this annual report;

4.       I am responsible for establishing and maintaining  disclosure  controls
         and  procedures (as defined in Exchange Act Rules 13a-15 and 15d-15(e))
         and internal  control over financial  reporting (as defined in Exchange
         Act Rules  13a-15(f) and 15d-15(f))  for the small business  issuer and
         have:

         a)       designed such disclosure controls and procedures or cause such
                  disclosure  controls and  procedures  to be designed  under my
                  supervision,  to ensure that material  information relating to
                  the  small  business   issuer,   including  its   consolidated
                  subsidiaries,  is made  known  to me by  others  within  those
                  entities,  particularly during the period in which this annual
                  report is being prepared;

         b)       designed such internal  control over financial  reporting,  or
                  caused such internal  control over  financial  reporting to be
                  designed  under  our   supervision,   to  provide   reasonable
                  assurance regarding the reliability of financial reporting and
                  the preparation of financial  statements for external purposes
                  in accordance with generally accepted accounting principles;

         c)       evaluated the  effectiveness  of the small  business  issuer's
                  disclosure  controls  and  procedures  and  presented  in this
                  report  our  conclusions   about  the   effectiveness  of  the
                  disclosure  controls  and  procedures,  as of  the  end of the
                  period covered by this report based on such evaluation; and

         c)       disclosed  in this  report  any  change in the small  business
                  issuer's  internal  control  over  financial   reporting  that
                  occurred during the small business issuer's most recent fiscal
                  quarter that has materially affected, or its reasonably likely
                  to materially  affect,  the small business  issuer's  internal
                  control over financial reporting; and

5.       I have  disclosed,  based on our most  recent  evaluation  of  internal
         control  over  financial  reporting,  to the  small  business  issuer's
         auditors and the audit  committee of small  business  issuer's board of
         directors (or persons performing the equivalent functions):

         a)       all  significant  deficiencies  and  material  weakness in the
                  design  or  operation  of  internal   control  over  financial
                  reporting which are reasonably  likely to adversely affect the
                  small business issuer's ability to record, process,  summarize
                  and report financial information; and

         b)       any fraud,  whether or not material,  that involves management
                  or other  employees who have a  significant  role in the small
                  business issuer's internal controls over financial reporting.


Date: April 14, 2005

/s/ Francis Chang
Francis Chang
Vice President, Finance and Administration
(Principal Accounting Officer)