SNS supports the formation of relationships between users in common interests and provides services allowing for clique management, sharing contents, and so on. It also has common functions such as acting as primary platforms smoothing the sharing and distribution by combination with various contents. Hence, questionnaire has been conducted to users of all of Twitter, Facebook and KakaoStory, and the factors affected by each service are presented by statistical analyses of the survey and the results are resolved by dividing them into complete and instrumental social capital. This study will be able to provide a standard for users to select SNS according to their purposes and contribute to development of new SNS or improvement of existing ones.