Abstract: The theories and practices of Knowledge Management(KM)have drawn the attentions of many scholars and enterpreneurs.But they fail to come to consensus on the way of practising KM.Knowledge is the object that needs to be managed.To understand,monitor or even contol the flow of knowledge are the basis of successfully accomplishing KM project.The researches of knowledge flow are focused on describing concepts or modelling the knowledge of patents or cites of paper through the statistical analysis or investigations.Petri Nets is used to model knowledge flow which can not only describe the topology of knowledge distribution,but also be used to calculate the storage,flux and velocity of knowledge flow.With these characteristics,the managers can monitor and manage the flow of knowledge much easilier.Then the knowledge model based on Petri Nets is applied in astronautic enterprise.In the empirical research,this model’s ability on depicting knowledge flow is illustrated.Through the analysis of the current statue,ways could be found to improve the efficiency of knowledge flow to reach the goals of KM.

Key words: knowledge flow, knowledge management, astronautic enterprise, petri net