This study verified a participation behavioral model for sports tourists. The people participating in the 2004 Penghu Marathon Race of the Chinese Worldwide were invited to fill out the questionnaires for testing the structural relationships among variables of the participants' exercise experience, watching sports programs experience, the attractiveness of sport tourism, participation motivation, participation satisfaction, and participation loyalty. According to the analysis by structural equation modeling. It showed that: First, the participants' exercise experiences and watching sports programs experiences did not have a significant influence on the participation motivation, while the attractiveness of sports tourism had a significant influence on participation motivation. Second, the participation motivation had a significant influence on participation satisfaction. Third, the participation motivation had a significant influence on participation loyalty. Fourth, the participation satisfaction had significant influence on participation loyalty. The findings provided the participation behavioral models for the sports tourists to the academic field. They also helped the sponsor of the Penghu Marathon Race to gain a better understanding about the participants. This study will contribute to the promotion and marketing strategies in holding tourist and athletically based Marathon sports in the future.