Abstract Good credit report items can help credit rating inquirers to evaluate their customers¡¦ credit correctly, and reduce the possibilities of delinquent loans efficiently. However, there are still many items that need to be improved in regards to policies, evaluation items, and methods used by domestic banks. This research is based on the understanding of the credit business of the bank to investigate credit rating by using questionnaires. It has sifted the possible factors, which could cause delinquency loan while making loans, and used the method of factor analysis to understand if there is any difference on understanding possible affective factors of delinquency loan between different bank groups. It is expected to make the theory and practice as mutual proof and provide reference resources to the savants, who are interested in researching the credit business of banks and the credit policy making of the banks. According to the research: I. There are five remarkable factors for understanding from 20 important factors that result delinquency loan on individual credit between the bank groups, which have more or less delinquency loans. The five different factors are: 1. The borrower has no proper occupation and ability to repay a debt. 2. The expected finance resource of the borrower does not have the ability to repay a debt. 3. The dealing rate, which is given to the borrower, does not fit in with the rules. 4. The inquirer has not evaluated the guarantee with the centralized evaluation method. 5. Affected by the factor of external economic situation. We can see from the result that the group that has less delinquent loans has paid more attentions to the five factors listed above. It is possible that the banks have made careful policies regarding credit to reduce the risk of delinquent loans under the situation of gliding economic. II. We use the factor analysis to divide the possible affecting factors of the delinquent loan on individual credit into eight events. There is a remarkable difference on external economic factor between both bank groups. This fact shows that under the situation of bad economic, the bank group that has less delinquent loans has paid more attention on this factor. Therefore, they would use credit policies, which are made more carefully. Keywords: Factor Analysis, Delinquency loan