This paper studied the design method of the LQG selftuning controller to suppress the flutter of a wing. The flexible wing model with a single trailingedge control surface was used in this study. The online identification was used to obtain the timevarying parameters of the system, and the Kalman filter was used to estimate the states of the system. Then, the control law was determined by solving a set of discretetime algebraic Riccati equations. All the developed algorithms were implemented on the Simulink platform. The simulation results show that the developed controller is effective and robust.