Abstract: Using the improved BP net technique, a new methd fordetermination of strength parameters of landslide zone soil is presented. Based on analysis of some factors affecting strength parameters, taking data of some landslides as training and testing samples, trained by momentum method, the prediction model of stregnth parameters is prososed. The results show that the model has a high precision, this method has been successfully used in calculating strength parameters of Gushubao landslide zone soil, and obtained results having good agreement with those by other common methods.