The frontal view, top view and cross sections of low drag car body were parameterized with control points and curves. Then the two dimension car body was optimized by design of experiments and local refinement methods. The global optimum results were obtained. Two three dimension car bodies without wheels were built based on the optimized two dimension car bodies，and their coefficients of aerodynamic drag were as low as 0.057 and 0.089 respectively. They could serve as low brag basic bodies for the future research of an ideal car. The agreement between test results and numerical results indicates that this parametric modeling method of low drag car body is feasible.