Abstract: ObjectiveTo study the contribution of bio-psycho-social factors to smoking behavior in Chinese adolescents.MethodsA cross-sectional survey was conducted among 1453 senior middle school students aged from 15-18 years recruited in Shanghai in 2000.A standardized self-administrated questionnaire was designed to obtain information on smoking,pubertal maturation timing,and several personality and social variables.ResultsStudents'smoking behavior was related to many factors.Depression、peer smoking、higher sensation-seeking、less of parental monitoring and less of security were significant risk factors for boys to experiment smoking.Whereas,peer smoking、earlier pubertal maturation、lower academic achievement、less of parental monitoring、less of security and lower self-efficacy were significant risk factors for boys to current smoking.And for girls,peer smoking、suicidal ideation and less of parental monitoring were significant risk factors for ever smoking.ConclusionApart from the knowledge education of tobacco,it was a pressing need to pay more attention to those athigher risk of smoking initiation,to support psychologically,and to train the life skill.