Based on the statistical and processing work for the peak acceleration data of Wenchuan MS8.0 earthquake in 2008,the statistical relationship between PGA and distance from the fault,PGA isogram and the 3-D acceleration diagrams in three directions are obtained.The results show that the peak acceleration attenuated slowly along the seismogenic fault,but attenuated rapidly in other directions,and the fastest decay appeared in the region within 100 km from the fault.High values of the peak acceleration commonly recorded in a narrow belt on both sides of the fault.Comparison of recorded values with values from the acceleration attenuation formula for west China shows that the latters are smaller and attenuate faster,it is consideredly related with the earthquake rupture mechanism and the tectonics.