$eta$-Sialon powders were prepared by reduction-nitridation from mixture of Wando pyrophyllite and graphite as a reducing agent at 135$0^{circ}C$ in 80% $N_2$-20% $H_2$ atmosphere. As the reaction products $Si_2ON_2$, $eta$-$Si_3N_4$ a--$Si_3N_4$ and $eta$-SiC were observed. Additive agents of MgO, CaO, $Y_2O_3$ were used for promoting the reduction and nitridiation aeaction. The present study was conducted to investigate the effects of silica-carbon ratio ($SiO_2$/C=weight ratio), raction time gas flow rate pellet size and powder packing on synthesis of $eta$-Sialon from Wando pyropyllite.