Abstract: The rational approximation of offset curve of Bézier curve is obtained when a polynomial is used to approximate the norm of parametric speed of Bézier curve.The obtained rational curve and the offset curve of Bézier curve have the same higher derivates at the endpoints.If the method is combined with the subdivision method of curve, the rational spline curve with higher-order continuity is presented which is the approximation of offset curve.Numerical examples are given to show effectiveness of the method.The results are compared with other methods, and conclusions are made based on the numerical examples.

Key words: Bézier curves, rational approximation, subdivision, offset curves