Abstract: Different raw material system were adopted to synthesize high purity Ti3SiC2 without any reaction additives by vaccum solid reaction. The effect of synthesis conditions on powder′s purity was studied by X-ray diffractometer and the reaction process and mechanisms were also discussed. The results show that high-purity Ti3SiC2 could be synthesized by taking TiH2, Si and TiC powders as raw materials, and the purity of Ti3SiC2 was all higher than 90% and the highest purity could reach to 98.64%. The higher purity Ti3SiC2 could be synthesize at 1 400 ℃ when the ratio of TiH2, Si and TiC powders was 1∶1.25∶1.9, and the Ti3SiC2 started to decomposed at 1 500 ℃.