We have used rapid thermal chemical vapor deposition (RTCVD) technique to grow epitaxial SiC thin films on Si wafers without carbonization process by pyrolyzing tetramethylsilane (TMS). The growth rate of SiC films increases with TMS flow rate and temperature, but it dereases with temperature at higher TMS flow rates. The XRD spectra of the films indicate that the growth direction is along the (111) direction of β-SiC. IR and RBS measurements have been employed to analyze the chemical composition of the films. At 1100℃ TMS molecules dissociate almost completely into Si atoms, CH₄ and C₂H₂ gases. The growth me- chanism of SiC films on Si substrates without carbonization process has been proposed based on the analyses by TEM and QMS.