In order to improve the robustness and imperceptibleness of the image spread spectrum watermark algorithm, a new approach for optimization in 8×8 DCT domain using genetic algorithm (GA) was proposed. GA was used to choose the AC coefficients, which were modified to embed the spread spectrum watermark. The bands were varied to find the most suitable for image with different characteristics. Performance improvement with respect to existing algorithm is obtained by GA adaptive global search. The experimental results show that the proposed algorithm yields a watermark that is invisible to human eyes and robust to various image manipulation, and show that some special positions are the best choices for embedding the watermark. The authors also compare their experimental results with the results of the previous work of others.