Electromagnetic acceleration plasma generators, which are called Magneto-Plasma-Dynamic (MPD) arcjet generators, can produce higher-velocity, higher-temperature and higher-density plasmas than those of conventional thermal plasma torches, because MPD arcjet plasma is efficiently accelerated by electromagnetic body forces in MW-class input power operation. These properties are effective for deposition of rigid coatings adhering strongly to substrate surfaces. In the present study, we newly developed an ablation type MPD arcjet generator for titanium nitride (TiN) reactive spray coatings. The coatings were deposited onto steel substrate. The phase structure and the composition of the coatings were analyzed by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD), and their Vickers hardness were measured. These analyses showed that the MPD spray process could successfully form dense and uniform titanium nitride coatings. The properties of the titanium nitride coatings were highly sensitive to the titanium cathode diameter and discharge current.