We use hypothetical mergers between banks and insurance companies to analyze the ”would be” risks and returns of bancassurance in Taiwan. The mergers using the stock price data and industry-level data show that the insurance business would have increased the returns of banks, and decreased the bank risks as a whole Furthermore, appropriate portion of business in the property-liability insurance is indispensable to achieve the optimal integration. The results using companies accounting data also show that the business of insurance, especially the property-liability insurance, would have decreased the bankruptcy probability of banks.