Silicon carbide whiskers (SiCw) as a kind of high strength fibrous material are widely used in the reinforcement of metal, ceramic and polymer. In this paper preparation of Silicon carbide whiskers by carbon thermal reduction reaction from the mixture of Silica and carbon was investigated with an emphasis on the study of the effect of catalyst. Fe, Co, Ni and their compounds were used as catalyst in this study. Since vapor–liquid–solid (VLS) mechanism was found to be responsible for the growth of whiskers, the formation of catalyst and its subsequent evolution on whisker nucleation, growth and appearance was a subject of extensive research. The catalyst that has the best effect among iron, nickel, cobalt and their compounds was made certain by comparing the products.