1997 Asian financial crisis, it created the best opportunities for bank mergers in the world. First, Taiwan's banking industry became a fierce competition industry since 1991. Secondly, Taiwan's government also decided to promote bank reforms and bank mergers in 2000. Fourteen financial holding companies were established until 2006. Furthermore, in this paper we try to conduct a theoretical model. Based on the assumptions of bank's going concern and risk aversion, we wish to find out the optimal control of financial holding company. Our government can use the simple index to test the optimal adjusting analysis of Taiwan's banking sales rate.