Abstract: Based on some destructions of Shuangshusi reservoir during Minle earthquake, Ground Penetrating Radar is used to study the slide tendency of high slope at spillway right bank. The detecting mechanism of slide disease and typical radar image characteristics are analyzed. The location and degree of latent slide tendency of reservoir high slope after earthquake are diagnosed. The detecting results indicate that the GPR be carried out the detection and evaluation of slide tendency of reservoir high slope in China westward loessland.