Previous research claims that associational membership produces social capital. Employing the first wave of the Asian Barometer Survey conducted in 2003, this study investigates the development of social capital and its political consequences in South Korea. Rather than study simple association membership, I examine the quality of civil society (defined as associational commitment and interaction) that individuals pursue through membership. This, I believe, provides a close test of the theoretical impact of social interactions on political participation. The findings indicate that there is a positive association between voluntary activity and two modes of political activity (voting and campaign participation) in different ways and to varying degrees. Associational membership is a significant predictor of voting. In the case of the quality of social capital, associational interaction (talking politics with group members) turns out to be significant in encouraging participation in election campaigns. Overall, my findings on the role of social capital support Putnam's argument that group interactions foster democratic participation.