Changes in the financial environment make bank face great challenges, It is an important issue how to obtain the determinants of the impact on the bank's operating performance. In the present study, we employ the regression analysis, literature review and practical experience of specialist to define the factors which are classified into four dimensions: ownership structure, profitability, security and macroeconomic factors. Furthermore, we use the DEMATEL (Decision Making Trial and Evaluation Laboratory, DEMATEL) as the analytical method to catch the structurization of problem and the causual paths among the factors. The empirical evidence shows that the determinants of affecting bank's operation performance consist of NPL ratio, loan interest rate, operating profit margin, return on assets, earning before tax margin, return on equity and earnings per share. We uncover clearly the causal relationship between the factors. It would offer the business strategy and help the manager to cope with the rapid changes in the environment for the bank.