In this paper, We have designed silicon pressure sensor with center-bossed diaphragm which improving sensitivity and linearity by reducing diaphragm deflection. Designed center-bossed pressure sensor showed maximum deflection of 0.125㎛, maximum stress of 2.24 x 10^7 Pa and sensitivity of 27.67 mV/V.psi. As a result, diaphragm deflection was reduced to 1/160 that of diaphragm thickness and 1/35 that of square diaphragm. Also, sensitivity was increased 19 times compared to square diaphragm.