Background Angelica sinensis is a well-known traditional Chinese medicinal plant. We aimed to assess the genetic diversity and relationships in A. sinensis cultivars collected from different locations of China and also some other Angelica species. Results We employed an improved random amplified polymorphic DNA (RAPD) technique for the amplification of DNA materials from ten Angelica cultivars, and the results were verified by inter-simple sequence repeat (ISSR) analysis. Twenty six RAPD primers were used for RAPD, and the amplified bands were found highly polymorphic (96%). Each primer amplified 8-14 bands with an average of 10.25. The cluster dendrogram showed that the similarity coefficients ranged from 0.41 to 0.92. The similarity coefficients were higher among different cultivars of A. sinensis, and lower among different species. Twenty ISSR primers were used for the amplification, and each primer generated 6-10 bands with an average of 7.2 bands per primer. The cluster dendrogram showed that the similarity coefficients ranged from 0.35 to 0.89. Conclusions This study genetically characterized the Angelica species, which might have a significant contribution to the genetic and ecological conservation of this important medicinal plant. Also, this study indicates that the improved RAPD and ISSR analyses are important and potent molecular tools for the study of genetic diversity and authentication of organisms.