Abstract: A robust text watermarking algorithm is proposed to solve the problem of copyright protection for Chinese text documents in this study which watermarking structure and embedding strategy are comprehensively considered. Structure types and strokes of Chinese characters can be obtained through Chinese characters mathematic expression and the whole document is divided into two blocks by utilizing structure types of Chinese characters, the position selected to embed is chose by Chinese character’s strokes and the watermarking bit in each block. Watermarking bits with a robust structure is generated by chaos encrypting and hamming checkout coding. Positions of the destroyed watermarking bits can be judged exactly and block-checkout and hamming-checkout are used to recover them. The experimental result indicates that the proposed algorithm is robust and transparent.