This paper presents about the optimization design of Silicon resonant pressure sensor. The new idea is the Silicon circular resonator was used as the sensing resonator. This sensor is Lead-Zinconate-Titanate (PZT) driven and the resonant frequency shift also detected by PZT. This micro resonant pressure sensor works on the principle of resonant shift caused by the change of internal stress due to applied of the external pressure. First, we analyze the numerical relation of circular resonator. Then, Finite element analysis (FEA) has been examined for optimization for the size of Si circular diaphragm, size of the PZT patches and placement of the PZT was analyzed. And the fabrication process also presented in this paper. The pressure range is 0~0.1Mpa. The resonant frequency is about 102.29 kHz and the linearity of the output frequencies shift is so good under Silicon diaphragm small deflection limited.