The electrical resistivity of the composite MoSi2 SiC containing various SiC contents was calculated by a topological method. The results of theory and experiment were found to be in good agreement. The researching results indicate that the electrical resisitivity of the bulk composite can be increased by increasing the volume fractions of the higher resistivity SiC phase and reducing continuity of the MoSi2. The approach described may predict the SiC volume fractions and microstructures needed to obtain some desired electrical resistivity, and may provide insights into the final microstructure.