The powders and bulks product composed of TiC, Ti3SiC2, TiSi2 and Ti5Si3 were synthesized by mechanically induced self-propagation reaction (MSR) during mechanical alloying of 3Ti/Si/2C powders. The Ti3SiC2 content of the powders and bulks was about 17.6% and 58.2% (mass fraction, similarly hereinafter), respectively. A reaction mechanism for the synthesis of Ti3SiC2 by MSR was proposed. The mechanism indicated that Ti3SiC2 nucleated and grew in solid TiC and Ti-Si liquid. The effects of MSR and self-propagation high temperature sintering on the content and microstructure of Ti3SiC2 in products were discussed finally.