Abstract: This article has studied the influences of particle sizes and microstructures of WC on particle sizes and microstructures of TiC-WC solid solution(TiC-WC S. S.) and on the properties of cemented carbides. The results indicate that the particle size of TiC-WC S.S. increases with increase of particle sizes of WC. The subgrain size of TiC-WC S.S. decreases with increase of subgrain size of WC. Microstrain of TiC-WC S.S. increases with decrease of microstrain of WC. There is a good dependent relation of microstructures between TiC-WC S.S. and cemented carbide. TiC-WC S.S. with large subgrain size and low microstrain has higher transverse rupture strength and impact toughness.