In spite of many inherent advantages, foil bearing's design tools considered temperature effects are in the existence not much due to the non-linear property of bump foils. In this present, when the external force was applied to the foil bearing under the high temperature environment, the dynamic characteristics of the bump foils were investigated by plane strain-stress method of FE analysis. Test results are presented for the standard specimen which is thickness, 0.12mm, half length, 1.8mm and the bump height, 0.45mm, using by an high temperature exciter system up to 680 V. The bump foil is fixed at one end of the lower plate. Each pad is 50mm by 50mm and made of INC X-750 material. As the upper plate moves or vibrates to the vertical direction, bumps are deformed in both the vertical and horizontal directions. The measured data includes stiffness and damping of bump foil(l=1.8-2.3mm, h=0.45mm). These results agree with that of FE results. When the bump foil are heated up, the stiffness characteristics of bump foil bearings decreases linearly and the damping effect of bump suddenly decreases due to the Coulomb friction between the top foil and the bump foil, and the bump foil and the plate, also, thermal effect of bump foils.