The main purpose in this paper is to identify the role of financial institution that concurrently operates security business in the industry. By analyzing the developments of security business and the operation of financial institution, we try to figure out where the competitive pressure among the industry comes from. Furthermore, we apply Porter’s industry competition model to confer this issue. Besides, this issue is trying to explain the systematic risk of global financial market and the reason why the conglomerating investment banks in the United State deteriorated. It’s also important issue to become international investment bank for financial institution that concurrently operates securities business. In our research, all the security firms and banks in Taiwan face structural dilemmas of small operating-scale, high business homogeneity, insufficient innovation ability, and closed-end operating strategy. Thus, what kind of competitive strategy or market position for financial institution that concurrently operates security business should be taken to develop the securities business is also the topic we will discuss in this paper. The analyzing basis of this paper is the individual development background of target bank. According to SWOT model of enterprise competitive power, this paper also provides different strategy matching analysis and develops the optimal development strategy of target bank that concurrently operates security business. To sum up, based on the efficient allocation of the external competitive conditions and internal development resources, the optimal development strategies of target bank that concurrently operates security business are: 1. Focusing business development strategy. 2. Niche-oriented: corporate finance business. 3. Differential service: professional broker business. 4. Financial technology promotion. 5. Accumulating long-term development basis: 3P+1S strategy. In order to achieve the development strategies given above, target bank should reintegrate related business departments and reinforce the product line function of each reintegrated departments. Taking the business cost and limit of existing organization structure resource into consideration, this paper suggests that by means of underwriting convertible corporate bonds and asset exchange transaction as the main media to extend security business and to intervene in investment bank field in short-term. Furthermore, we hope that we can broaden the scope of existing marketing channel of current financial commodities and underwriting business of target bank from the experience of the strategies we suggested. In brief, the optimal development strategy of the target bank depends on the existing basis of corporate finance background. By the integration of independent derivative commodity and underwriting business department, our business activities are trying to develop diverse institution finance management and professional security brokerage. Considering the current bases and efficient cost strategies, we hope that we can initiate financial commodity services of niche and derivate production. Furthermore, in the future we can step by step expand our security business and investment banking affairs to global capital markets in the basis of target bank arrangement strategies in China, Hong Kong and Taiwan.