Abstract: Based on the Wenchuan ground motion, more than 400 sets of mainshock seismic records were selected and the characteristics of zero-crossing rates were analyzed. The result shows that:（1）under the same conditions, the zero-crossing rate of vertical and horizontal component of Wenchuan ground motion is obviously larger than that of horizontal component, which indicates that the high frequency component of vertical component is richer than that of the horizontal component, and the decrease of the zero crossing rate of vertical component is more obvious with the increase of time;（2）irregular terrain will increase the Wenchuan ground motion zero-crossing rate of non-stationary;（3）compared with the vertical component, the horizontal component attenuation change is small, indicating that the horizontal component of the frequency of non-stationary degree is weaker;（4）the attenuation curve of Wenchuan strong vibration is better, which can provide the data support for the parameter of zero crossing rate in engineering sense.