Abstract: The study introduced the theoretical model of social ecology and analyzed the mechanism through which the social ecological model may influence the sport and health behaviors. The findings revealed four core principles:1) the influence on sport and health behavior is comprehensive and multifaceted; 2) there are interactions among different facets; 3) there exist differences among facets of various systems in social ecological model; 4) the most effective intervention to change the individual's sport and health behavior is to conduct collective intervention from multi-facets. Moreover, based on the five-level social ecological model, the study discussed the effects of various social ecological factors on adolescents' health behaviors. The findings showed that different factors from various facets of social ecological system have different effects on adolescents' sport and health behaviors. The factors, which interact and influence among different facets, mainly take effects in individual psychology, family, school, peers, and community settings.