Online learning participation drives online learning and promotes learning satisfaction; however, participation in online learning is inherently low because there is a lack of monitoring learning information. The purpose of this study is to develop a visualization system to enhance online learning participation based on learning behaviors and social presence, and to evaluate its effects. The visualization system provides learners' learning information from two perspectives: individual information on learners' learning behaviors and group information on discussion scripts. An online university course was augmented with a visualization system, and 66 first year university students registered for it. The results of the Mann-Whitney-U-Test showed that students who accessed the system's pie-chart function (regarding the frequency of using reading functions in groups) tended to highlight important content at a higher frequency and achieved higher final scores which were calculated based on the mini-reports, discussions and final reports than those who did not. Furthermore, compared to those who did not use the system's heatmap function (regarding the reading time in groups), students who used it read more of the learning material during the online course and received higher final scores.