This study investigated the online flow frequency among college students in regard to different internet activities, and analyzed the effect of flow frequency on internet addiction. This study surveyed 525 undergraduate internet users in Taiwan by using convenience sampling to question participants. In this paper, analysis of variance (ANOVA) was performed to examine the differences in usage activity regarding the level of flow frequency. To test the effects of the flow frequency factor on perceived internet addiction, multiple regression analysis was performed for the constructs of internet addiction from different internet usage activities. The analytical results indicate that online gaming by undergraduates in Taiwan reporting higher level of flow frequency than their primary internet activities and their flow frequency of online gaming will predict internet addiction.