System modeling is a widely used technique to model state-based systems. Several state-based languages are used to model such systems, e.g., EFSM, SDL and State Charts. Although state-based modeling is very useful, system models are frequently large and complex and are hard to understand and modify. Slicing is a well-known reduction technique. Most of the research on slicing is code-based. There has been limited research on specification-based slicing and model-based slicing. In this paper, we present an approach to slicing state-based models, in particular EFSM models. Our approach automatically identifies the parts of the model that affect an element of interest using EFSM dependence analysis. Slice reduction techniques are then used to reduce the size of the EFSM slice. Our experience with the presented slicing approach showed that significant reduction of state-based models could be achieved.