Abstract: Objective To explore the influence of advanced puberty timing on smoking and drinking habits of adolescents,and to provide some guidelines for policies making and school works.Methods A total of 2 484 teenagers from 11 to 16 years old,were selected from May 2015 to January 2016 in 10 middle schools.According to measur boy's testicular volume and public hair growth,girls's breasts and menarche age youths were divided into early group,timely group and delayed group and were given the self-designed questionnaires.Data between two groups was compared.Results The reporting rate of smoking and alcohol drinking was 19.89% and 32.93%,which was 25.15% and 41.10% for the male and 14.07% and 23.89% for the female.Early group smoking and drinking ratio were significantly higher than other groups(x2 =14.311,P<0.01;x2 =9.699,P=0.002;x2 =26.640,P<0.01;x2=7.796,P=0.005).Conclusion The prevalence of smoking and drinking among adolescents in Chengdu is higher.Youths with advanced puberty timing is more likely to have smoking and drinking habits,which needs attention of educators.