The challenge of dynamic environment requires managing business processes with the ability to adapt to changes and to collaborate in activities. As a promising technology to process management, agent technology with its flexible, distributed and intelligent features has been studied in numerous studies. However, most existing approaches are special and ad-hoc. They have not looked much into the nature and characteristic of agents and their rational behaviours in process management. This paper intends to investigate the mechanism how to build intelligent agents in dynamic process management from the view of knowledge engineering. An agent-oriented approach to dynamic process management with its knowledge engineering is discussed, and a three-layer knowledge model of intelligent agents is proposed. By exploiting the knowledge involved in dynamic process management and transforming it into a computational model, this work provides an essential support of developing agent-oriented approaches to business process management.