The credit risk management is one of the most importance issues for the financial institutions. This is also indicated by the Basel Committee on Banking Supervision which formalizes the universal approach to measure credit risk for financial institutions. As we know, banks earn profits from loans, and enterprises are main borrowers. Thus, credit risk management for enterprise loans is a major concern for banks. This paper adopts a formal methodology, data envelopment analysis, to assess the credit risk of enterprise. The model is illustrated by listed, OTC and emerging companies from 1998 to 2007 in Taiwan. First, this paper applies factor analysis and data envelopment analysis to derive the credit scoring of domestic corporations. Second, the results of credit scoring were validated by regression analysis and discriminant analysis. Consequently, this paper proposes a methodology, data envelopment analysis, which will help banks to measure the credit risk of loans. The empirical results can provide banks to make effective lending decisions and face the Basel Capital Accord in the future.