Based on the CMBOK (Construction Project Management Body of Knowledge) Framework previously developed in early study by the authors in conjunction with use of some questionnaire surveys and personal interviews with industry professionals, the authors analyze interactions among the entities in the CMBOK framework for the extraction of pivotal entities of construction project management and identify twelve pivotal entities in construction project management, then verify the existence of twelve pivotal entities in real construction project management of construction company and checked the validity of the entities with a real case of interaction phenomenon. This research provides the construction industry with a starting point for improving construction project management efficiency by identifying the pivotal entities.