OBJECTIVES: This study aimed to determine the general predictive factors of change in drinking behavior and to provide materials for preventing drinking problems during early adulthood through examining genetic and psychosocial factors affecting the change of drinking behavior in college students. METHODS: The subjects were 101 male college students, a part of 534 students who had completed the previous study in 2000. In the present study as a 6-years follow up, we reassessed the drinking pattern and psychosocial variables and compared the results with previous data of the same subjects. To identify factors affecting the current drinking pattern, we used stepwise multiple regression and logistic regression analysis. RESULTS: D allele (ALDH2) was found to reduce the degree of drinking and suppress problematic drinking, and C allele (TPH) had a suppression effect on problematic drinking. Drinking motive had a direct effect on the degree of drinking and problematic drinking. Negative cognitive expectancy had a direct effect on problematic drinking. CONCLUSION: Authors found some factors affecting the change of alcohol drinking behavior in college students and confirmed that there were hierarchies of significance among these factors. These may be applicable as variables for predicting drinking behavior in early adulthood.