Based on near field ground motion data of reservoir earthquakes in Xinfengjiang,Oroville,Monticello,etc.,attenuation curves of their peak acceleration have been obtained by using statistical method.The result shows that the peak acceleration of reservoir earthquakes is much higher than that of natural earthquakes.For example,at site one kilometer away from the epicentre,the peak acceleration of a M_S5.0 earthquake at Xinfengjiang is 20 gal higher than that of a natural earthquake with the same magnitude,and that of earthquake in Oroville or Monticello is 100 gal highter than that of natural earthquake. But acceleration of reservoir earthquakes attenuates much faster than that of natural earthquake,and peak period of response spectra and duration of ground motion are rather short.