本文根据我国西部地区的实际观测资料,说明在震前波速异常期间,和达图一般都要出现较明显的弯曲,因而和达曲线的曲率可作为监视震前波速异常进程的一项新的辅助指标.文中介绍了和达曲线的二次逼近方法,给出了我国西部地区一些强震及中强震(M_s>5.0)前后和达曲线曲率变化的初步探索结果.最后,文章对所得结果作了简单的讨论,并指出了在地震预报中的应用. Based on the observed data in the western part of our country, this paper shows that during the anomalous wave velocity anomalies, the curves of Datong curve and Datu curve should be more obvious, so the curvature of the curve can be used as a new aid in monitoring the anomalous velocity anomalies before the earthquake Index.The paper introduces the quadratic approximation method of the curve of arrival and gives the preliminary exploration results of the curvature changes of some curves before and after the strong and moderate earthquakes (M_s> 5.0) in western China.Finally, A simple discussion, and pointed out the application in earthquake prediction.