Recently we have carried out inelastic neutron scattering measurements on Li2RuO3 to understand the nature of the phase transition at 550K. We have seen a clear inelastic magnetic signal below 5meV at low temperature, which convert into a diffuse scattering at 578K. In this proposal, we propose to carry out high resolution powder diffraction experiment in order to understand the origin of the metal-insulator transition found in this two dimensional system. As we have done for Tl2Ru2O7 before, we will collaborate with a theoretical group to carry out LDA+U band calculation using our high resolution data. Using our high quality sample, we will measure diffraction patterns from 300 to 700 K. Since we plan to take both long and short runs with fine temperature steps, we request a total of two days of beam time at HRPD to complete the proposed experiments.