Abstract: ObjectiveTo explore the sex behavior among the adolescents working in small service establishments and to provide scientific basis for making intervention strategy.MethodsA convenience sample of 1 210 adoleseents working in small service establishments from 7 provinces/cities was investigated.ResultsAmong the adolescents,42.2% were sex active;80.6% had their first sex with the lovers,but only 28.0% used condom.There were 60.3% of the adolescents having sex in recent 3 months,51.3% using condom,and 16.0% having commercial sex.ConclusionThere were high risk sex behavior among adolescents working in small servic establishments.Peer education with the professionals,as well as appropriate reproductive health service should be provided to the adolescents.