The Silica-Carbon mixture was made with addition of carbon black in the composition which monodispersed spherical fine silica was formed by the hydrolysis of ethylsilicate, mole ratio of Carbon/Alkoxide was 3.1 and $eta$-SiC powder was synthesized by reacting this mixture at 1,350~1,50$0^{circ}C$ in Ar atmosphere. The results of this study are as follow : (1) The purity of synthesized $eta$-SiC powder was above 99.98% and it was in cubic modification with lattice constant of 4.3476$AA$. (2) The rate-controlling steps varied with the reaction temperature for the syntehsis of $eta$-SiC in this study ; nucleation and growth of $eta$-SiC at 1,350~1,40$0^{circ}C$, interfacial reaction at 1,45$0^{circ}C$ and diffusion described by Jander Equation at 1,50$0^{circ}C$. (3) When the rate-determining step was nucleation and growth, the activation energy was about 87.8kcal/mol.