This paper describes the characteristics of poly (Polycrystalline) 3C-SiC grown on SiO2 and AlN buffers, respectively. The crystallinity and the bonding structure of poly 3C-SiC grown on each buffer layer were investigated according to various growth temperatures. The crystalline quality of poly 3C-SiC was improved from resulting in decrease of FWHM (Full width half maximum) of XRD and FT-IR by increasing the growth temperature. The minimum growth temperature of poly 3C-SiC was 1100 °C. The surface chemical composition and the electron mobility of poly 3C-SiC grown on each buffer layer were investigated by XPS and Hall Effect. The chemical compositions of surface of poly 3C-SiC grown on SiO2 and AlN were not different. However, their electron mobilities were 7.65 ㎝2/V.s and 14.8 ㎝2/V.s, respectively. Therefore, since the electron mobility of 3C-SiC/AlN was two times higher than that of 3C-SiC/SiO2, AlN is a suitable material, as buffer layer, for SiC growth with excellent crystalline quality.