A new flow model is developed for the analysis of compression molding of sheet molding compounds(SMC) and penalty finite element formulation is presented to predict flow front progressions more accurately. In this model SMC is assumed nonisothermal fluid, which has different viscosities in extension and in shear. The flow is allowed to slip at the mold and is resisted by friction force which is proportional to the relative velocity at mold surface. For the verification of the model, the press force and flow patterns are compared with those of experiments and available results by other works in this field. It is also demonstrated, using the computational procedure described and the proposed model, that optimal initial charge shapes for the filling can be effectively computed.