Ti-Al and Ni-Al intermetallic compounds were formed by the combustion synthesis of elemental powder mixture and the effect of third element addition on the synthesized compounds was investigated. By the addition of the third element Ag to Ti-Al or Si to Ni-Al, the ignition temperature for combustion synthesis decreased due to the appearance of eutectic melts between Al and added element. Besides, even by hot pressing at 973K for 300s with a sintering pressure of 0.6MPa, each element completely reacted to form homogeneous intermetallic compounds and voids were hardly remained in the synthesized compacts. This is probably due to the infiltration into the void by eutectic liquid phase with a high fluidity. By the combustion synthesis of precursor compacts preplaced on metallic substrate, joining of intermetallic compounds with metallic substrate was achieved simultaneously with the formation of intermetallic compounds.