In this paper, the influences of ultrafine Ti(C,N) additions on the microstructure, mechanical properties, wear resistance and corrosion resistance of micron Ti(C,N)-based cermets fabricated by powder metallurgy methods are investigated systematically. The results reveal that the proper ultrafine Ti(C,N) additions in micron Ti(C,N) cermets generate an inhomogeneous microstructure with a hybrid distribution of micron and ultrafine grains and increase the hardness of cermets obviously. However, the excess ultrafine Ti(C,N) additions induce the decline of hardness. Moreover, the proper ultrafine Ti(C,N) additions in Ti(C,N) cermets may resist the crack propagation and enhance the strength and toughness of cermets. Additionally, the combination of ultrafine and micron Ti (C,N) grains in cermets may obtain excellent wear resistance. The increasing grain boundary induced by the ultrafine Ti(C,N) addition may impair the corrosion resistance in the acid solution environment.