The purpose of this study were: (1) to compare the differences of sport commitment and related factors for male and female long-distance runners; (2) to compare the differences of sport commitment and related factors for long-distance runners who participated for different distance; (3) to explore the factors that can predict sport commitment for long-distance runners. A total of 358 long-distance runners who participated in 2013 Kin-Men Marathon were served as participants. All participants were asked to complete the demographic data and the inventory of sport commitment. The one-way MANOVA and stepwise multiple regression statistics methods were used to analyze all collected data. The results from the current study indicated that: (1) male long-distance runners had higher score in personal investment and social constraint than female long-distance runners. (2) runners who participated in marathon had higher score in personal investment and sport commitment than those participated in half-marathon; runners who participated in marathon had higher score in sport enjoyment than those participated in half-marathon and 11.2 K; runners who participated in 11.2 K had higher score in involvement opportunity than those participated in marathon and half-marathon, and marathon runners had higher score than half-marathon runners in involvement opportunity. (3) sport enjoyment, involvement opportunity and personal investment were three effective predictors that can predict long-distance runners' sport commitment. Finally, based on the results of the current study, the implications and suggestions for future studies are discussed.