Abstract: Based on one actual engineering site profile of Chengdu area, studied the effect of shear wave velocity of seismic wave inputting interface on the peak acceleration. The results show that both the peak ground acceleration and the peak acceleration underground 5 meters increased logarithmically with shear wave velocity's increasing. The increase rate was the fastest under small earthquake input, the increase rate of moderate earthquake input was second, major earthquake input increase was slowest. When the wave velocity value increased from 500 m/s to 800 m/s, the peak acceleration increased more than 20%, the biggest reached 32%.The experience formula can be used as a conversion formula of the peak acceleration in this region and provide reference for seismic design of engineering personnel.