The purpose of this study is to describe the design of the information sharing mechanism in online problem-based learning environment. Problem-based learning engages learners in collaborative and authentic learning experiences, knowledge and skills are inquired and acquired by collaboration of groups of learners. With the infusion of web-based technology, this study developed the information sharing mechanism to meet learners? needs of exchanging resources and opinions during the process of collaboration. This mechanism is an open, dynamic and evolving resources pool composed of instruction resources, group-gathering materials and personal learning references. Learners are able to easily give and get information within groups, and also contribute resources for the specific subject of the course.