At present about the causes of China's banking bad credit assets, mostly ืconcentrated in the theoretical circle to consider from the system, they think that the fundamental cause of China's banking bad credit assets is institutional factors. Even it is generally believed that in a mature market economy countries commercial Banks non-performing assets belongs to the technical issues, and stated-owned enterprises’ non-performing assets in the transition economy can be summed up in institutional problem. That is to say, in the implementation of market economy countries’ financial market , information asymmetry is the main reason of bad bank assets, while in China there is no information asymmetry problems in financial markets or information asymmetry is not the fundamental cause of non-performing assets of Banks in China. Through the analysis, we think that institutional factors is a special reason of non-performing assets of China's banking sector, the unbalanced and asymmetric information is the common cause i of banking bad credit assetsn domestic and foreign. Because at present our country lacks channels and effective form of communication between Banks and enterprises, once the bank loans ,credit funds have into the enterprise capital circulation, enterprise master full information of the operating conditions for its own funds, but for bank produces a "grey box" effect, information about the capital operation at a disadvantage position. Some enterprises try to tamper with the accounting statements, and provide favorable project appraisal and the related data, and some even provide false material and evidence to obtain bank credit