Knowledge management (KM), through learning from past projects, has been considered as an effective means for continuous improvement. However, many KM initiatives have failed to meet this expectation, due to the top-down, controlled approach and an ineffective transferring mechanism. To address this challenging issue, this paper proposes a project-based KM system that helps to acquire and transfer knowledge, using blogs on a project basis instead of knowledge maps. Project blogs store various types of project information and knowledge including communications among project participants, and interconnecting personal blogs of project participants with project blogs would improve collaboration between project participants. Moreover, the proposed KM system could realize "information pulling" of lean construction by delivering prerequisite knowledge of an activity at the time that project participants are ready for that activity. Stored knowledge, with the contextual information extracted from the schedule database, is automatically "pulled" to project participants.