Ti3SiC2 bulk materials by hot-pressing sintering were presented through adding a little amount of B2O3 as a low-temperature additive in different raw-material systems. In one system, elemental titanium, silicon and active carbon were used as reactants with a molar ratio of 3: 1: 2. In another one, titanium carbide, titanium and silicon reacted together with a molar ratio of 2:1:1. At different temperatures, samples were synthesized by hot-pressing with a heating rate of 30°C min-1 before 1200°C and then 10°C min-1 to peak temperatures, holding for 2h. The effect of sintering temperature on the purity of Ti3SiC2 was investigated at the range of 1200°C to 1500°C. The products mainly contained Ti3SiC2 with TiC as the second phase. In some cases, Ti5Si3 appeared as well. When sintered at 1300°C, above 98vol% Ti3SiC2 was obtained in the elemental system. The roles of B2O3 additive were considered as weakening the thermal explosion reaction in the elemental mixture and affecting the diffusion procedure at low temperature in both systems.