A new and simple hydrothermal process has been used to synthesize single crystalline silicon carbide nanorods. The synthesized silicon carbide nanorods have a length of about 1 mu m and nearly same diameter of about 40 nm. We have observed that the nanorods possess a well-defined single crystalline structure with a thin layer of amorphous silica on the surface. The X-ray diffraction analysis demonstrates that the structure of silicon carbide nanorods is beta-SiC. Raman shifts of the silicon carbide nanorods are discussed and the oxide-assisted growth mechanism is proposed to explain the formation and growth of silicon carbide nanorods.