In order to explore the roles of perceived harm of drinking and drinking behavior in the effect of perceived peer drinking norms on drinking-related problems, 1216 first-and second-year college student drinkers from four universities in Zhejiang province, China, were investigated with Drinking Norms Rating Form, Perceived Harm of Drinking Questionnaire, Alcohol Consumption Questionnaire, and College Student Alcohol Consequences Questionnaire. Results indicated that:(1) perceived peer drinking norms significantly positively predicted drinking-related problems, and the relationship between perceived peer drinking norms and drinking-related problems was mediated by drinking behavior;(2) perceived peer drinking norms affected drinking-related problems via the sequential mediation of perceived harm of drinking and drinking behavior. This study reveals that the effect of perceived peer drinking norms on drinking-related problems in college student drinkers is a sequential mediating process.