Si3N4(p)-SiC(p) composites were prepared by gas pressure sintering at 190$0^{circ}C$ for 1 hour. $alpha$-SiC with average particle size of 0.48${mu}{ extrm}{m}$ were dispersed from zero to 50vol% in $alpha$-Si3N4 with average particle size of 0.5${mu}{ extrm}{m}$. Y2O3-Al2O3 system was used as sintering aids. When 10vol% of SiC was added to Si3N4, optimum mechanical properties were observed; relative density of 98.8%, flextural strength of 930MPa, fracture toughness of 5.9MPa.m1/2 and hardness value of 1429kg/$ extrm{mm}^2$. Grain growth of $eta$-Si3N4 was inhibited as the amount of added SiC was increased. SiC particles were found inside the $eta$-Si3N4 intragrains in case of 10, 20 and 30vol%SiC added composites.