Representation of a circular arc plays an important role in CAD. However, the existing methods are not friendly to designers. In this paper, a series of methods are presented to construct the circular arc with C-Béier curves. In order to compare with the old methods, so-called characteristic ratio is proposed. As a consequence, the C-Béier curves with degree higher are better than the lower. Specially, the quintic C-Béier curve can construct the whole circle.