V2O3 and VN nanocrystals have been conveniently synthesized from thermal ammonolysis of the precursor VOC2O4•H2O in a resistance tubular furnace at 500°С and 780°С for 30 min, respectively. The products were characterized by X-ray diffractometer (XRD)、X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) techniques. The average particle sizes of V2O3 and VN are both in the ranges of 20~35 nm. The evolution from precursor to hexagonal V2O3 and then to cubic VN was explored. The crucial factors，such as the reaction temperature and time，have also been discussed.