Online purchasing behavior is the process of buying products or services through internet media. The online buying process has different steps like physical buying behavior. The specificity of the process of buying through the internet media is when potential customers use the internet and are looking for information related to the goods or services they need. This study aim to find out effects of the social factor, psychological, convenience, and information quality both partially and simultaneously on online buying behavior among students of FEB UMP Purwokerto. This type research is with field research. The sample consisted of 97 students UMP Purwokerto who had made online purchase. The sampling technique was the slovin formula. The data were collected by a questionnaire. The results showed that factor social, psychological, convenience, and information quality affect online buying behavior. As for the partial, only variabels social and convenience that have significant effect on online buying behavior and variables psychological and information quality have no effect on online buying behavior. Coefficient of determination (R2) of 0,340 show that 34,0% of online buying behavior is affected by the social factor, psychological, convenience, and information quality.