Smoking and drinking are common behaviors in China. Social norm is an important factor which predicts and influences individuals ’ behaviors. This article summaries the psychological mechanism of social norm to provide suggestions on making policies to overcome smoking and drinking problems by using social norms. We review the psychological mechanisms of descriptive and injunctive norms,and their effects on behaviors respectively. We also consider the influence of indigenous culture on social norms’ effects on behaviors. On the basis of the results,we provide specific suggestions on how to take social norms into consideration in making policies to overcome smoking and drinking problems.