Abstract: This artiele studied the influence of the composition of TiC-WC solid solution on the microstructure and properties of grade YT15 cemented carbide. The grain size of the tungsten carbide and graphite inclusions in the cemented carbide decrease with the decrease of tungsten carbide content or with the increase of titanium carbide content, in TiC-WC solid solution. The profile of TiC-WC grains in cemented carbide becomes better when TiC content in TiC-WC solid solution amounts to 40-50%. As for the properties of cemented carbide YT15, the maximum trans-verse rupture strength can be obtained when the TiC content in TiC-WC solid solution is 30%. The optimum havdness at room temperature and long curing duration can be obtained as the TiC-WC solid Solution contains 50%TiC. YT15 cemented carbide Will has higher hardness at the temperature of 400℃ and 800℃ as TiC-WC solid solution contains 75% TiC