Abstract: In CAGD,polynomials are usually employed as the basic functions for the interpolation of curves and surfaces. In this paper, a new kind of approximation curves and surfaces based on the trigonometric functions is developed, which retains the main superiority of B-splines method and meets C³ continuity while the cubic B-splines can only meet C² continuity. Besides, the present method works for the case of ellipses,while polynomial does not. An example is given to illustrate the design of a modeling configuration.