DC plasma jet method was applied to produce ultrafine particles (UFPs) of Ni-Ti-N system. Mixture of elemental powders of pure Ti and pure Ni was used as starting material. Mixture of Ar and N-2 gas was used as plasma forming gas. The obtained UFPs were analyzed by X-ray diffraction (XRD), conventional TEM and analytical high resolution TEM (HRTEM). XRD and selected area diffraction in TEM indicated that the UFPs are composed of Ni, TiN and TiNi phases. It was revealed by TEM observation and EDX analysis that Ni particles were spherical and TiN particles were cubic bounded by {100} planes. Composite UFPs were often seen. Typical morphology was "dumbbell type". The other type of composite UFPs, which is called "dice type", can be seen occasionally. The structures of the dumbbell-like composite UFPs were studied in detail by HRTEM. In addition to the previously reported Ni / TiN dumbbell-like particles, we have also found TiNi / TiN particles. Orientation relationship between the TiNi and TiN phases is {211}(TiNi) // {100}(TiN), < 111 > (TiNi) // < 100 > (TiN).