This study explores two issues, one is to investigate the determinants of net interest margins and bank risk-taking from 1993 to 2001 in a partial universal banking system, taking Taiwan as our example, and the other is to provide some empirical evidences of exchange ratio determination of bank mergers in Taiwan. In the first topic, the partial universal banking system here is a mix of the conventional commercial banking system (whose activity is mainly loan-deposit taking) and the universal banking system (engaging in both loan-deposit and investment activities). We employ the recently developed method of the panel data threshold regression method to estimate the determinant function of the net interest margin and bank risk-taking model. It is found that the corporate governance plays an important role in explaining the recent behavior of the banking industry. The empirical results show that the net interest margins in the commercial banking system are affected by credit risk, interest rate risk, the degree of leverage and management quality, unlike the net interest margins in the universal banking system which are more sensitive to only-credit risk and the degree of leverage. Moreover, the relationship between managerial ownership and credit risk taking behavior is inverse U-shape in the commercial banking system, consistent with the corporate control hypothesis, unlike U-shape relation in the universal banking system that supports moral-hazard hypothesis. In the second topic, we not only extend Larson and Gonedes (1969) merger exchange ratio model to taking account of market risk and more participants but also apply Marsh-Merton dividend behavior reduced form (1987) to estimate the expected post-merger price-earnings ratio. Taking the first case of the bank merger according to the Financial Institution Merger Law as our sample, we find that the L-G model indicates the interval of exchange ratios that enhance, or at least not cause any diminution in the wealth positions of all parties to a proposed bank merger. Also, the bargaining area offers some information to help merger candidates to negotiate final actual exchange ratio.