This study aimed to analyze the Effect of Security, Ease, and Trust on Online Purchasing in TOKOPEDIA. Objects in this study in TOKOPEDIA while the subject in this study are consumers who have bough in TOKOPEDIA. This study used 100 responden selected using Non Probabillity Sampling technique throught Purposive Sampling method with criterion of Yogyakarta society who had bought in TOKOPEDIA. In instrument testing in this study using Multipe Regression Test which operated using SPSS program. Based on the analysis that has been done, the results obtained that the security, easy and trust together have a positive and significant effect on purchasing decisions, security has a positive and significant effect on purchasing decisions, ease has a positive and significant effect on purchasing decisions and trust has a positive and significant effect on purchasing decisions .