This paper reports that Zn3N2 powders of high quality have been synthesized by nitridation reaction of Zn powders with NH3 gas in 500 ml/min at a nitridation temperature of 600 degrees C for 120 min. X-ray diffraction (XRD) indicates that Zn3N2 powder has a cubic structure with lattice constants a=9.788 angstrom. Observations through scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) show that Zn3N2 powder is of nanowire structure. X-ray photoelectron spectroscopy (XPS) tells the differences of chemical bonding states between Zn3N2, and ZnO, and confirms the formation of N-Zn bonds.