Abstract: The degree reduction of generalized Ball curves of Wang-Bézier type is discussed by
perturbation and the best uniform approximation respectively. The approximation error is given. The
experimental results demonstrate that the effect of the best uniform approximation is better than that
of perturbation. If the error cannot be obtained in advance, the original curve can be subdivide firstly,
and then reduce the degree by using of perturbation part by part. The degree reduction method of
WBGB curves enriches the theory system of generalized Ball curves effectively.

Key words: WBGB curves, perturbation method, best uniform approximation