Ferromagnetic iron nitride has fascinated researchers owing to its amazing magnetic properties for spintronic applications. We have prepared single-phase epitaxial thin films of gamma'-Fe4N on single-crystal MgO(100) substrates by using dc magnetron sputtering. X-ray diffraction revealed that the substrate temperature and the annealing time were the most important parameters for single-phase epitaxial growth of the films. Atomic force microscopy and scanning electron microscopy were utilized to investigate the surface morphology of the films. Angle dependent magnetic anisotropy was observed in epitaxial thin films of gamma'-Fe4N. A superconducting interference device was utilized to explore the magnetic and the electrical behaviors of gamma'-Fe4N films at low temperatures.