Themogravimetric analysis was used to investigate the kinetics of the $Si_3N_4$ formation from Korean rice hulls in the temperature range from $1990^{circ}C$ to $1370^{circ}C$. The experimental results indicated that the reaction rate controlling step in the overall process is the diffusion of CO gas from the surface of carbon particle to main body of $N_2$ gas fluid through the stagnant gas film around the carbon particle. The kinetics followed a nearly linear rate law at the initil reaction stage. The activiation energy for the formation of $Si_3N_4$ from Korean rice hulls was 43.5Kcal/mole.