Abstract: Events of December 1982 in Huairou County, Beijing, and of July 1982 in Jianchuan, Yunnan were recorded at one station in Beijing City and at four stations in Eryuan area, Yunnan respectively. Dividing the spectra (for P and S waves) of the large events in the series by the spectra (for corresponding P and S waves) of the smaller events in each region, we have determined the high frequency source spectral decay rate to be -2 in both cases. Through trial and error method, we are able to determine the appropriate constants QP and Qs that correct the in dividual spectra to the proper high frequency decay-rate. It is found that a QP of 800 and Qs of 550 can adequately compensate for the attenuation of the waves in Beijing area. For the Jianchuan area, Yunnan the corresponding values are 900 and 400.