Burning velocities of methane/air mixture at pressure ranging from atmospheric pressure to high pressure up to 1.0 MPa and mixture temperatures of 300 K and 573 K were measured for Bunsen-type flame stabilized in a high pressure chamber using OH-PILF. Based on the contours of the mean progress variable, <c>, turbulent burning velocity was determined. Bending tendency of S_T/S_L curves with u'/S_L was also seen at high pressure and temperature. The turbulence Reynolds number region where the bending occurs corresponded well to the region where the smallest scale of flame wrinkling measured as a fractal inner cutoff approaches the characteristic flame instability scale. Flame instability for the flow without turbulence was also measured and the increase in nominal burning velocity was confirmed at high pressure and high temperature.