Abstract: The application of the workflow management in IT fields is discussed generally. The basic concepts of the workflow are studied in detail. After put forwarding the workflow management reference model, its components and characteristics are probed into. Then, according the reference model, the three kinds of interoperability among (between) the workflow engines are referred. Through analyzing four general design modes of the workflow interoperability, their characteristics and features are discussed and compared. Then, the classification of the interoperability of the workflow is elucidated. The two ways to realize the interoperability of the different workflow system are addressed. Finally, the shortcomings and the trends in the future of the current workflow interoperability are also touched on.