Web-based knowledge-sharing communities, which are supported by countless voluntary Internet users, are in widespread use today. We explored a number of characteristics of interpersonal communication among participants based on their questioning and answering behaviors. A questionnaire survey on participants of Yahoo! Chiebukuro, one of the most popular knowledge-sharing communities in Japan, was conducted, and access data of their behavior in the community were collected. Based on 7,989 survey samples and access data, we found that there were several significant differences in their behavior and motivation based on their participation style, question content, and gender. Results also suggested that information was exchanged and accumulated actively in the community and interpersonal communication of community participants was developed by an aggressive need for information acquisition and subsequent social support.