The purpose of the study is to explore the antecedents of college athletes’ behavioral intention of vaccination in Mainland China based on the extended theory of planned behavior. Quantitative method was used to address the issue of the present study. Researchers developed the questionnaire, and purposive sampling was adopted to select respondents who are members of the varsity sports team. Online questionnaire (WJX.CN) was utilized to collect data; a total of 981 valid online questionnaires were recruited. Descriptive analysis and structural equation modeling partial least squares were used to analyze the collected data. The findings indicate that the college athletes’ perceived attitudes, subject norms, and perceived behavior control toward vaccination significantly affect their behavioral intention of vaccination. Attitude is the most crucial antecedent affecting college athletes’ behavioral intention of vaccination. Furthermore, the extended antecedents of commitment, motivation, and knowledge significantly influence college athletes’ attitudes toward behavioral intention of vaccination. Attitude is a partial mediator between commitment, motivation, knowledge, and behavioral intention of vaccination. The explanatory power of the model is 71.8%. College athletes’ positive psychological status and knowledge would promote the vaccination attitude, which is the key to enhancing their vaccination behavior.