Online community as a business model has gotten much attention in online market. And it has been recognized as an increasingly important tool for better understanding and relationships with customers. Thus, There are needs for conducting researches, such as those being performed in social psychology area. Due to the lack of current researches on online community, variables that have been considered in social science and factors in relationship marketing are adopted in this study. The primary purpose of this research is to develop and test a model that explains the process of how sense of online community through relationship quality influences customer loyalty. The major findings of this study are as follows: First, sense of online community was found to have a positive influence on relationship quality. Second, relationship quality was found to have a strong positive effect on customer loyalty. Finally, relationship quality was found to have a mediation effect between the sense of online community and the customer loyalty. Implications of these findings are discussed for researchers and practitioners.