In accordance with the two-dimensional structural dependence of color cartoon image and the entropy coding theory in data compression, a method of color cartoon image lossless compression by eliminating the structural redundancy is presented. At first it is proved that the entropy of image can be reduced by way of removing the solid region. Then the method of removing the structural redundancy is discussed. The color image is divided into three kinds of region--background, solid region and gradient color region. In order to effectively recover data, the improved Freeman chain code and color seed are used to save the removed solid region information. We apply in sequence this method and the entropy coding method to eliminate the structural redundancy and the statistical redundancy for full color cartoon images. Experiments show that the proposed method results in reduction of bit rate by 25% compared to using directly universal methods of image lossless compression.