Abstract: Vector maps are widely used in the geographic information systems (GIS)，military surveying and mapping and so on. Watermarking techniques for vector maps are widely used for protecting the copyright of digital maps,preventing from illegal forgery and authentication. They have been well developed recently. Firstly the characters and appraisement criteria of watermarking for vector maps were given. Then the analysis of spatial domain, frequency domain,zero-watermark and multi watermark were discussed. The comparisons showed the advantages and disadvantages of these algorithms. Finally the development direction and possible research targets were pointed out.

Key words: Data hiding,Digital watermarking, Vector map,Appraisement