The purpose of this study was to determine the effect of convenience, trust, security, service quality and risk perception on online purchasing decisions Studies in college student users shopee). This research uses quantitative research methods, non-probability sampling techniques, obtained through purposive sampling is a method of determining the sample based on certain criteria. This research sample of 130 respondents. The research method used in this study is multiple regression analysis. The results of the analysis show that partially convinence, trust, service quality, have a significant effect on purchasing decisions, while security has no influence significant and risk perception influence negative on online purchasing decisions. Furthermore, the results of the simultane ous analysis show that convenience, trust, security, service quality and risk perception affect on online purchasing decisions. The result of determination coefficient analysis of 62,5%, while the rest of 37,5 % influenced by other variabels not examined in this research. Quality of service is the most influential factor to online purchasing decisions.