Abstract: Based on bit-decomposition technique and multiresolution-decomposition technique,a digital image watermarking algorithm is proposed in this paper. By multiresolution-decomposition technique, the decomposed watermarks of different resolution are embedded into the corresponding resolution of the decomposed original image, which makes the watermark be adapted to the original image. The chaotic Arnold map is utilized to generate the watermarking-embedding-position in order to enhance the security of watermarking. The watermarking can be extracted without the original image because the embedding procedure is based on the quantized method. Experimental results show that the proposed algorithm is robust to some image processing operations.