Abstract: A novel watermarking algorithm based on quantization and relationship in singular value decomposition domain is proposed.Firstly,cover image is subdivided to non -overlapping blocks of size 8×8.Secondly,perform 1-level discrete wavelet transform for each selected blocks,and do singular value decomposition on the low and high frequency sub -band,respectively.Finally,the biggest singular value of low and high frequency sub -band are modified by exploiting quantification and relationship method to embed preprocessed watermarking image, respectively. Experimental results show that the proposed algorithm has good transparency and robustness. Compared with other algorithms,it has better performance for most attacks.