Grid is becoming a new infrastructure for scientific computing and cooperative work, it becomes more important and urgent to provide grid workflow to construct and manage the grid applications. The grid workflow based on dynamic modeling and scheduling is presented, which consists of user portal, resource management component, grid services management, performance management, grid workflow engine, and its advantages cover the dynamic modeling according to changing grid running environment and dynamic scheduling adopting to the performance of grid system by performance evaluation and optimization. Then the prototype implemented on the Globus is introduced. Finally the experiments of genome sequencing based on shotgun algorithm are analyzed and the results are promising.