Abstract: An investigation on stability of heated panels insupersonic air flow is carried out in this paper. A nonlinear aeroelasticmodel for a two-dimensional heated panel is established using Galerkinmethod. The quasi-steady piston theory is employed to calculate theaerodynamic load on the panel and the even temperature field is considered.At first, the static and dynamic stabilities for flat panels are studied byusing Lyapunov's indirect method and the stability boundary curve isobtained. Then the static deformation of a post-buckled panel is calculatedby Newton iterative approach, and the local stability of the post-bucklingequilibrium is analyzed. The results show that a two-mode model is suitablefor panel static stability analysis and static deformation calculation; butmore than four modes are required for dynamic stability analysis. Theeffects of temperature elevation and non-dimensional parameters related topanel length/thickness ratio, material density and Mach number on thestability of heated panels are also investigated. It is found that panelflutter (secondary instability) may occur at relatively low aerodynamicpressure when there are several stable equilibrium points for theaeroelastic system of heated panels.