Rapid development of information technology has generated a new industry and market. In particular, network technology such as the Internet and other computer networks made transaction activities switched from traditional offline commerce to e-commerce. Among them, digital content is bit-based object which is created and distributed through electronic environment. In particular, many entertainment contents such as the music, the movies, and the computer game softwares are main products. Although digital content commerce has high potential demand, it lacks the consideration about the factor related to maintaining existing customer such as customer loyalty and switching costs. There has been a number of research on customer loyalty and other factors affecting it in the traditional electronic commerce environment, but there is a lack of research which examines the characteristics of digital content. The study about the effect of switching costs on customer loyalty in digital content commerce is necessary because the customers of digital content commerce market are from those of other e-commerce market or traditional offline commerce market. In addition, customer loyalty and switching costs are important factors because they may build up greater customer retention. For that reason, this study focused on examining the relationships among switching costs, antecedents for switching costs, and customer loyalty in online digital music service industry. The study has three major purposes: (1) to find antecedents of switching costs on digital content commerce and examine effect of antecedents for switching costs; (2) to identify effect of switching costs on customer loyalty in digital content commerce and examine moderating effects of alternative attractiveness; (3) to identify the differences of antecedents for switching costs by contents transmission type(streaming service and downloading service). And, the online digital music service industry is selected in this study since there are many users and transactions incurring. To accomplish these purposes, a survey questionnaire was developed and distributed to 256 informants. Survey instrument was developed based on previous research and pre-established survey items. Total of 206 surveys are collected and used in the data analysis. Among the respondents, 56.8% is male and 43.2% is female. Also, 86 responses were streaming service user group and 120 responses were download service user group. These data was analyzed using regression analysis. Major findings of empirical analysis can be summarized as follows. First, switching costs have positive effect on customer loyalty in digital content commerce environment. Second, the influence of switching costs on customer loyalty increases under conditions of high alternative attractiveness. Third, DRM convenience and breadth of use have positive effect on switching costs. The findings imply that the digital content provider should pay more attention to switching costs in addition to customer satisfaction in order to attract customers. Also, increasing the convenience of DRM use by securing the convenience of user interface and expanding the support device and increasing the service use scope by providing diverse value-added service helps to create a switching barrier. The result of the study can become a practical use in marketing strategy for maintaining existing customer. In particular, switching barrier is very important under conditions of high competition in the online music service market. This study can be used as a basis for further studies about customer retention in digital content commerce.