Although interest in knowledge management has been growing recently, its history is still short. However, related theories have been developed and accumulated considerably in various adjacent academic disciplines. This paper presents an analytical framework that integrates three variables—the characteristics of knowledge, the processes of knowledge management, and the units of analysis in knowledge management—and proposes theories developed in adjacent disciplines according to this framework along with research directions for knowledge management. Here, knowledge is classified into explicit knowledge and tacit knowledge according to its characteristics, and the processes of knowledge management include the acquisition, creation, dissemination, storage, measurement, and utilization of knowledge. The units of analysis in knowledge management are divided into four levels: individual, organization, industry, and nation. In other words, if the existing theories studied in adjacent academic disciplines are systematically synthesized and linked to knowledge management, a comprehensive theoretical framework for knowledge management can be established within a short period of time.