Abstract: The whole process of knowledge development in enterprises is analyzed and summarized into three phases：knowledge capture, storage and reuse. These subprocesses are linked together through knowledge conversion and joining. Ontology is used to unify the formal description of knowledge throughout the whole process of knowledge management (KM). A basic KM system framework is brought forwards, and the major problems involved in the implementation are outlined. An example of KM system for Computer Science College of Zhejiang University is given to illustrate the processes.