In order to further improve the robustness of watermarking algorithm b ased on support vector machine (SVM),a double watermarking algorithm based on SV M in complex Conto urlet domain and Krawtchouk moment is proposed in this paper.Firstly,the blue component and green componen t are extracted from the RGB host image.The algorithm makes full use of the invariance of Krawtchouk moment invariants to translation, rotation and scaling,and the better local reconstruction characteristics of Kra wtchouk moment.The lower order Krawtchouk moment invariants of the blue component are calculated for constructi on of robust watermarking. Then the green component image is decomposed by two-level complex Contourlet tr ansform.In the low-frequency components,the local correlation training model of image in the same scale is e stablished by using support vector machine.The watermarking image is adaptively embedded and extracted according t o the prediction results of the established model.A large number of experimental results show that the proposed algorithm is not only invisible but also robust against the common image processing,such as median filtering,Ga ussian noise and JPEG compression,and against some kinds of geometric attacks,including rotation,sca ling and clipping.It outperforms the image watermarking algorithm based on support vector machine in wavelet doma in or Contourlet domain.