Abstract: High frequency scattering theory, including physical optics, physical theory of diffraction and equivalent electric current theory, were used to calculate the radar cross section of various scattering resources of missiles, such as flat plate, circular cylinder, quadric surface, edge and so on. Combined with the equation of traveling wave and dihedral reflector, the RCS of total missile was calculated. The measurements and calculations agreed with well. It has been proved that the analysis to missile scattering resources is right, and the modulation to missile scattering resources is quite exact. So high frequency method can satisfied the engineering analysis need for the RCS calculation of missiles. The major scattering resource in top direction is radar antenna or infrared head, in side direction is dihedral reflector formed by missile wings, missile body and wings.