The goal of an approach to Adaptive Knowledge Management (AKM) of project-based learning (PBL) is to intensify subject study through guiding, inducing, and facilitating development knowledge, accountability skills, and collaborative skills of students. Knowledge development is attained by knowledge acquisition, knowledge sharing, and knowledge utilization. The determined conceptual framework shapes an adaptive process for managing knowledge. The process realizes adaptive self-formation of knowledge-heterogeneous collaborative groups of students, adaptation of an instructor's assessments to knowledge dynamics of individual students and collaborative groups, dynamic choice of control tests for individual students and projects of suitable complexity for collaborative groups, and adjustment of an instructor's control questions to complexity levels of projects performed by groups. The accountability skills are developed by creating and sharing accountability of students for successful performance of projects. The development of collaborative skills is resulted by collaborative performance of the projects. AKM of PBL is realized by two phases. The first phase is devoted to planning teaching and learning the subject matter. The second phase is aimed at promoting development of knowledge, accountability and collaborative skills of students through guiding performance of the sample project, monitoring and assessing the sample project outcome, fostering students' adaptive grouping, organizing collaborative performance of the group projects.