Since the financial reform in Taiwan, confronted by the globalized competition in the financial industry, local banks pressingly need to develop methods to retain quality customers in order to protect and expand niche. For these banks, commercial friendship is an important form of relationship in relationship marketing, which is an important marketing form. Relevant to decision-making patterns, personal characteristic is a critical aspect affecting decision-maker's behaviors. Therefore, this research determines the effects of the small and medium-sized enterprises (SMEs) financial decision-makers' personality characteristics on their loyalty to correspondent banks. This research uses questionnaire as the method to obtain data, and uses Pearson's r as the primary analytic method. The results are: the commercial friendship and the loyalty have positive correlation, and the SMEs financial decision-makers' personality characteristics have significant moderation effect on the commercial friendship and the loyalty.