Abstract: The hybrid technique to integrate the Inagaki modes with the general asymptotic waveform evaluation(GAWE) is proposed for computing the radar cross section(RCS) of a perfect electric conductor(PEC). In the analysis, the orthogonality and completeness of the Inagaki modes are used to construct the solution space of a matrix equation. Hence, the solution of the equation can be obtained by combining the basedvectors of the solution space with a set of coefficients, which can be determined by the GAWE technique at a given frequency. The results of numerical examples verify that the novel technique is effective in computing RCS.