High speed vehicles are exposed to severe aerodynamic heating during flight. The thermal load can affect material properties and induce thermal stress, thermal deformation, even thermal buckling. Therefore, the dynamic stiffness and modal characteristics change. Experiments are carried out on an aluminum alloy panel to investigate the thermal modal characteristics pre-and post-buckling. The panel is heated using a quartz lamp heating system. The thermal buckling characteristics are first experimentally tested, and the critical buckled temperature is obtained. Then, a series of high temperature modal surveys are carried out. The modal frequency, damping and shape are identified at each temperature distribution. It is shown that the modal frequencies reduce firstly as the temperature increases. However, after the critical buckled temperature, the modal frequencies increase with the augment of the temperature. Since the sensitivities of different modal parameters with the same thermal loads are different, the 3dr and 4th modal shape are swapped during the heating process. The modal damping increases with the raise of temperature.