To provide efficient grid services, a mechanism for services composition is needed. This paper proposes a novel approach to perform semi-automatic grid workflow composition. It presents an extended architecture to facilitate workflow of Semantic Grid services and demonstrate how OWL-S based grid services are composed by using their semantic description. Our combined filter techniques utilize both the traditional category classification and service semantics. In specific, category filter distinguish it from other work in this area. We address practice and feasibility of composition and collaboration among services, meanwhile, a prototype has been built to illustrate our method.