SiC nanorods were synthesized through carbothermal reduction of SiO by C nanocapsules (CNCs) or amorphous activated C (AAC). The synthesized nanorods were characterized by high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectrometry (EDS). The nanorods formed during a reaction between SiO and CNCs were straight. They displayed a preferential orientation of the growth axis; Which was either parallel or normal to the [111] direction. The nanorods formed during reaction between SiO and AAC consisted of straight and curled parts or chains of SiC nanoparticles. The straight parts were aligned in the [111] direction. A surface of the rod tip was covered with a thin amorphous layer, 1～3 nm thick; Containing Si; C and traces of O. Formation mechanism of the SiC nanorods was proposed.