The purpose of this study was to investigate factors influencing students' satisfaction and dissatisfaction with an Online Learning Community (OLC). The OLC was a Web-based system that was used to supplement school science curriculum. Data was collected from 62 Korean high school students using an open-ended questionnaire. The factors related to the learners' satisfaction with the OLC involved "usefulness," "easiness of use," and "fun factor." The reasons underlying the students' dissatisfaction with the OLC were classified into three categories, including "environment problem," "student problem," and "teacher problem." In general, the learners considered OLC as helpful for their learning and recognized their difficulty in getting used to the Web-based system. It is strongly suggested to utilize a Web-based system like OLC, as an educational tool for teaching and learning science.