The chemical states of hydrogen in Zr (purity, 99.7%) and Zircalloy-2 (nuclear grade) oxide films produced in air at 673K for 18h were studied by photoelectrochemical (PEC) measurements and electrochemical impedance spectroscopy (EIS) measurements. Some oxide films were implanted with 100keV H + ions and oxide films were also obtained by the oxidation of Zry-2 hydride. From the PEC measurements Zry-2 oxide films with and without hydrogen have a band gap energy of 4.8eV and two sub-band gap energies of about 4.0 and 3.0eV. The flat-band potential for hydrogen implanted Zry-2 oxide film and that obtained by oxidation of Zry-2 hydride oxidation film was increased. Those results show that hydrogen in the oxide film caused the impurity level in the original band gap, which was confirmed by EIS measurements using Mott-Schottky analysis.