Social trust and political participation are crucial indicators for examining the operation of a democracy. According to the traditional argument, social networks, including personal contact and group participation, are the main sources encouraging social trust and political participation. However, the accumulation of social trust and political participation might become more difficult along with the decrease in social networks in a changing society. Can the Internet become a new source for social trust and political participation?

This study incorporates the Big Five personality traits into the rational choice theory to explain individual political participation. It argues that three factors in the rational choice framework – selfefficacy belief, perceived benefits and civic duty – play a pivotal role in mediating the relationships between personality traits and political participation. In accordance with previous research, this study finds that extraversion, agreeableness, conscientiousness and openness to experience exhibit  significant direct impacts on political participation.