Abstract: A family of optimized hypersonic waverider derived fromconical flow fields is generated and studied; the detailed viscous effectsare included within the optimization process using the referencetemperature methods. A non-linear simplex method is used to find thewaverider configuration for the maximum lift over drag ratio, viscousoptimization is completed at Mach number 6, attitude 30km, andcone angle from 5^\circ to 10^\circ. Shapes of waveriderwith high lift over drag ratio are obtained, and the resultsare verified with CFD. The results show that for the optimized designwaverider, the lift over drag ratio of waverider is the maximum at acertain cone angle; the skin friction drag and wave drag are nearlyequal; volumetric efficiency, slenderness,span over length ratio increase with the cone angle.