This paper presents the comparative studies of two growth processes of 3C-SiC epilayers, heteroepitaxial growth of 3C-SiC on Si (100) substrates and homoepitaxial growth on 3C-SiC substrates by the method of low pressure CVD (LPCVD) using vertical type reactors. The growth temperatures of heteroepitaxy and homoepitaxy were 1330degreesC and 1530degreesC, respectively. The thickness of these epitaxial films were about 100mum. The root mean square of the surface roughness of the homoepilayers were around 0.4 nm (10mum x 10mum) measured using an atomic force microscope (AFM). The typical values of the FWHM of XRD-omega scan rocking curve was around 150 arcsec. A free exciton peak of 3C-SiC and the peaks originated from N dopants were observed for the homoepilayers in PL spectra. The free exciton peak was not observed for the heteroepilayers.