A MoSi2/SiCP composite was synthesized by in situ reactive sintering of a mixture of molybdenum, silicon, and carbon powders. Its microstructural features were studied by X-ray energy dispersive spectroscopy (EDS), conventional transmission electron microscopy (CTEM), and high-resolution transmission electron microscopy (HREM). It was determined that the composite was composed of alpha-MoSi2 and beta-SIC, There were no specific orientation relationships between the MoSi2, matrix and SiCp, because the MoSi2 and SiC were formed at 1450 degrees C by the reaction of solid Mo and C and liquid Si. The abrupt change occurring in the microstructure of the composite is explained by the presence of an interface between MoSi2, and SiCp, where no observable SiO2 amorphous layer or particles were found. Microtwins and stacking faults were frequently observed in {111} planes of SiCp.