New metal organic framework (MOF); C12H12CuN2O4 as a hydrogen storage material has found, and it absorb 2.6 wt% hydrogen at 70 bar. Surprisingly, the absorption curve is still upward suggesting that more hydrogen will be stored in the material. Although the crystal structure was refined by Rietveld analysis using x-ray diffraction data, the hydrogen sites and occupancies are unknown due to its low sensitivity to x-ray. The hydrogen sites are predicted by a Monte-Carlo simulation, and there are several stable sites in the materials. In order to reveal the hydrogen sites/occupancies and the maximum hydrogen capacity in the material, we have planned to perform neutron diffraction experiments under a high hydrogen pressure.