Abstract: Silicon carbide precursor was prepared by sol-gel method using tetracthyl orthosilicate (TEOS) and active carbon as raw materials. Then, the powdered silicon carbide was synthesized by carbonthermal reduction reaction at 1400-1600°C. Such a powdered silicon carbide is a mixture of particles and whiskers. The pyrolysis process of silicon carbide precursor was analyzed by thermogravimetric (TG) and differential scanning calorimetry (DSC), and the composition and structure of powdered silicon carbide synthesized at different temperatures was analyzed by X-ray diffraction. The effects of the volume ratio of ethanol (EtOH) to TEOS and ammonia concentration on the morphology of products were investigated with the formation mechanism of silicon carbide whiskers and particles discussed preliminarily.