To represent curves and surfaces unified, many commercial soft-wares adopt non-uniform rational B-spline (NURBS) as the method. The NURBS method includes Bézier, B-spline and so forth. In surfaces smoothing Class A surfaces of auto-body are a kind of surfaces that have high desire. While different representing methods can fit curves and surfaces with prodigiously different qualities and efficiency. So the representing methods and degree selection of curves and surfaces for auto-body are fundamental issues that auto-body engineers must be solved. Based on analyzing the character of Bézier and B-spline representing methods, Bézier method is adopted to represent Class A surfaces of auto-body according to the desire of auto-body surfaces. At the same time, the degree of curves and surfaces for auto-body is limited between 2nd-7th according to the oscillation of high degree curves and surfaces and continuity desire. The example verified that the Bézier method can improve the quality and efficiency.