Credit granting is not only one core business but also the major profit source of banks. Non-Performing Loan Ratio (NPL Ratio) is an important index to evaluate the quality of credit granting and to influence profitability of banks. Recently, NPL ratio, which soared to record level, of local banks does not only hurt their asset quality but also threaten their surviving space due to the changes of internal structure, overbanking, internationalization of local banking industry, economic recession, the subprime crisis in 2007. Theoretically, banks have their own credit granting policy and credit examination system; however, there is soaring NPL ratio to cause huge NPL losses in banks because of the differences of credit grating practices. Nevertheless, there are some local banks which have lower NPL ratio. Therefore, this research is to help us to understand the possible factors of overdue loan that happened in corporate banking, and try to discover the key factors. Also, try to sampling those key factors from the past experiences for future crediting reference. The main profit from a bank is the margin of deposit and credit loan interest. Therefore, the overdue loan is highly related to a bank¡¦s profit. Moreover, it is necessary for banks to pay more cost to make up the losses which are caused by the NPL. Certainly, it is safest way for banks to acquire 100% collaterals for creditors¡¦ right, although 100% collaterals could be acquired, the creditors cannot ignore the impacts (on the creditors¡¦ profitability) of the necessary litigation expenses for disposing the collaterals. As a result, fully recognize the customers¡¦ credit condition before drawing is the only way to avoid the NPL loss and ensure the profit.