Abstract: In this paper,coseismic water-level changes of Wenchuan M_S8.0 earthquake in Sichuan area are analyzed.The results indicate that the coseismic water-level changes are mostly of step rising variation accompanied by continual slow change,tidal distortion,impulse and jump.The distribution of the coseismic water-level step changes is not uniform.The closer to the epicenter the more step rising anomalies there are,but the amplitude of the water level changes do not simply decrease with the distance to the epicenter.