Cooperation with foreign strategic investors is one of the most effective ways for china's commercial banks to increase their efficiency.This paper analyzes the possible effects of introducing foreign capitals into domestic commercial banks and by utilizing the Data Analysis Envelopment method it measures the efficiency of individual banks both before and after the entry of foreign capitals.Using possible causes for the banks' efficiency changes as independents variables,a linear regression model is built.The result shows that the rate of capital sufficiency has no direct impact on the banks' performances while the structure of property is closely related to them.In the end,some suggestions are given based on the practical analysis results.