The purpose of this study was to understand the impact of international volunteer's participation motivation and organizational commitment on self-efficacy. The Volunteer of college students in Taiwan were enrolled in this study. 120 questionnaires were sent out; 430 questionnaires were returned; 116 questionnaires were valid; the usable rates were 96.7%. The formal questionnaire was based on “international volunteer's participation motivation scale,’’ “organizational commitment scale,’’ and “self-efficacy scale’’ as research tools. The data gathered were thus analyzed using descriptive statistics, Pearson correlation analysis, multiple regression model, AMOS, and Gray relation Model. The results indicate that (1) There was a significant positive relationship between international volunteers’ motives and self-efficacy (2) Organizational commitment and self-efficacy has a significant positive relationship. (3) There was a significant positive relationship between personality characteristics and self-efficacy.