Abstract: According to zero-watermarking, a zero-embedding algorithm for multiple watermarks was proposed based on wavelet and chaos. Matching matrixes were structured with wavelet zerotree structure, and used to load multiple binary watermarks scrambled by chaotic sequences. The zero-embedding of multiple watermarks ensured the watermarks' invisibility thoroughly, and could implement a blind detection by stage. Experimental results show that the technique has stronger robustness, better security, dependability and feasibility.