Reduction of sonic boom intensity and improvement of lift to drag ratio are important in aerodynamic design of the future supersonic transport. They are inevitable matter especially for supersonic business jet (SSBJ), for which it will be required to cruise over land with low sonic boom. Therefore its shape must be optimized to reduce its sonic boom intensity and improve its lift to drag ratio. An shape optimization of SSBJ is conducted by using CFD and the waveform parameter method for analyses, and genetic algorithm for optimization.