Abstract: In order to analyze the sensitivity coefficient s of piezoelectric lamina in terms of Hamilton canonical equation, based on the H-R ( Hellinger-Reissner) variational principle of piezoelectric materials, the expression of operator was deduced for Hamilton canonical equation, and the governing equations of static response were established for piezoelectric plates simply supported on four sides as well. According to the definition of sensitivity analysis, the hybrid governing equation of static response and sensitivity coefficient s was obtained by uniting Hamilton canonical equation and the equation of sensitivity. The mechanic, electric parameters and the sensitivity coefficients of static response would be gained by this hybrid governing equations at the same time. This algorithm simplifies the process and improves the efficiency of calculation and stability. The result s of numerical examples, compared with those of the finite difference methods, show that the present solution is efficient.