UML is an useful object modeling tool and workflow technology is the core to realize business process modeling, analysis, optimization and management and finally realize business process automation. The paper firstly introduces the basic conception of UML and Rational Rose and the composition and function of workflow management system, and then discusses the advantages of using of UML and Rose in modeling a workflow management system. It also gives the reason why system modeling is so useful to a software system. Finally, it gives an example about how to use Rose to model effectively in workflow management system of a flow of improving minepsilas security management. At requirements analysis stage, use case diagram, sequence diagram, collation diagram and class diagram can be design first, because these can help us to understand the detail of system well. At system design stage, it is necessary to define package, refine class diagram and design other diagrams.