This study explores the relationship between Internet use, political participation, and social capital. I propose that it is important to distinguish the quality and quantity of Internet use, and accordingly, this study examines two different indicators of Internet use: time spent on the Internet and motives for Internet use. Time spent on the Internet is further categorized into time spent on the Internet for work and time spent on the Internet for pleasure. Motives for Internet use include information search, social interaction and entertainment. The relationship between time spent on the Internet and Internet use motives and political participation as well as social capital is examined. Moreover, it is proposed in this paper that the Internet functions as an important media for political participation. Therefore, the relationship between Internet use time and motives and the three unique types of political participation via the Internet is explored, too.