Abstract: A new method is proposed for calculating supersonic unsteady aerodynamic forces in this paper.It combines the piston theory for unsteady flow with the conical flow theory for steady flow.Its essential feature lies in that the interaction of points on a wing neglected in the piston theory is approximated by conical flow theory.This method was applied to flutter calculations of 29 cases for wings with 10 different types of plan forms.The results have been compared with flutter test data obtained in wind tunnels in satisfactory agreement.The accuracy of flutter analysis improved by this method is much higher than that obtained by the piston theory.It is shown that this method is feasible and reliable for supersonic flutter analysis.It provides the advantages of briefer algorithms,higher numerical accuracy,less computing time and easier programming.