The jet characteristics of supersonic plasma jet spraying (SPJS) system were studied. Comparison of jet property was made between conventional plasma spray system and SPJS system. The results showed that the characteristics of the SPJS system are superior to the latter system. The particles velocities in the range of 400~800 m/s are obtained for supersonic plasma jet guns with 4.5 mm diameter nozzles and 60 l /min total gas flow rates, SPJS operate about 36 KW. The particle velocity is more than two times as much as conventional plasma jet spraying. The supersonic plasma jet is much longer than that of the conventional torch. It can bring about improvement for flying powder heated and accelerated and also prolong spray distance.