The ternary layered machinable Ti3SiC2 ceramics were synthesized at 1300°C by high-energy milling and hot pressing sintering using Ti,Si and C powder as starting material. The reaction mechanism was examined by XRD, SEM and thermodynamic analysis. The results show that Ti-Si-C powders were transformed to Ti, Si and little TiSi, SiC,Ti5Si3 intermetallics by milled for 18 hours. In this process, the little Ti and C transformed to TiSi phase in early stage, and then the most of residual elements reacted to form SiC and Ti5Si3 intermetallics. Finally, Ti, Si, SiC, Ti5Si3 intermetallics and TiSi reacted to yield Ti3SiC2 by hot pressing sintering. And the sintering temperatures had a significant impact on the yielded content of Ti3SiC2 phase. Besides. The Ti3SiC2 would decompose if the temperature was high enough.