The dynamical behavior of a hinged-hinged two-dimensional plate excited by supersonic flow is presented in this paper. The geometrical nonlinearity is considered using the large deflection plate theory, whereas the supersonic piston theory is employed to account for the effects of the aerodynamic force. A four-mode expansion has been used to reduce the original partial differential equation into a set of ordinary differential equations, which is then solved by the incremental harmonic balance method. In this study, the effects of the in-plane load are emphasized on the fluttering plate problem. The solution diagrams show that for a moderately high post-buckling load, several limit cycle oscillations are possible which have not yet been found beforehand. In addition, comparison of numerical results with other articles are made whenever data are available.