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. More importantly, the Big Five personality traits apart from agreeableness also exert significant positive indirect effects on political participation through self-efficacy belief, perceived benefits and civic duty. To sum up, this study provides new insights into the relationships between personality traits and political behavior and shows that dispositional traits can play some role in the rational choice framework to account for individual political participation.