Abstract: On the basis of the study of seismic geological environment and seismic distributive regularity in Qingjiang river basin and its neighbouring regions, 12 potential seismic source regions and their parameters of seismic activity were determined, The reduction regularity of regional seismic intensity and seismic influence intensity of the potential seismic source regions on the two dam sites of Geheyan and Shuibuya were analyzed. The seismic risk of the two dam sites were assessed by using Poission model, and ground were obtained. According to the comparison analysis of seismic risk fro the two dam sites, safety factor of Shuibuya dam site is larger than that of Geheyan dam site.