Abstract: Ultrafine powders of Ni-TiN were prepared by arc-discharge synthesis in an atmosphere of a H₂-N₂-Ar mixed gas. The phase, morphology, size distribution and oxidizing characterization were studed by XRD,TEM and DTA-TGA. Results show that the powder consists of three phases of Ni, TiN and Ni₃Ti. The morphology of the particles are three types, one is dumbell-like, second is dice-like and last type is spheroid. In air, the powders were evidently oxidized nearby 300℃ and the TiN particles were oxidized to dissolve at about 480℃.