Abstract: The paper aimed to explore the relative effect of best friend,parental factors on adolescent smoking cognition and smoking behavior.The confidential self-reported questionaire were administered by 1042 7^th to 12^th graders who were selected from two middle schools in Beijing,China.The result showed that:(1) best friend's smoking behavior and sr}king attitude had more significant effect on adolescent smoking cognition than parental factors;(2) adolescent smoking behavior was more influenced by parental factors than adolescent smoking cognition;(3) adolescent smoking cognition significantly predicted adolecent smoking behavior;(4) best friend's smoking behavior and attitude,parental smoking behavfor and adolescent smoking cognition directly affected adolescent smoking behavior,and best friend's smoking behavior and smoking attitude had indirectly influence on adolescent smoking behavior through adolescent smoking cognition;(5) compared with parental factors,best friend's smoking behavior had more significant effect on adolescent smoking behavior.

Key words: adolescent, best friend, parents,smoking cognition,smoking behavior