Service integration, the ultimate goal of Shanghai Grid, has created a necessity for more efficient workflow infrastructure. Workflow design tool is one core component that assists in defining workflow processes as well as providing graphical representation of process model through which users can have an easier understanding of the semantics of process. This paper discusses a workflow design tool for Shanghai Grid that has the following features. First, it combines graphical process representation and ECA rules in controlling Grid workflow process. Second, integration adapter of the Grid Workflow system is presented to facilitate the composition of all possible services. Finally, this tool supports hierarchical graph definition that allows workflow coursing and refinement. In this way, it extends the scope of resource sharing and offers a well-layered view for complicated workflow. Design principle and implementation details of workflow design tool for Shanghai Grid are also given in this paper.