Abstract: The arbitrarily primed polymerase chain reaction(AP-PCR) technique was applied to the analysis of the phylogenetic relationships among species of Chinese Sagittaria except S. natans which is not included in this study. One hundred and twenty-seven polymorphism DNA fragments were generated by ten arbitrarily primers and used to calculate the genetic distance. A phylogenetic dendrogram was constructed based on genetic distance by UP-GMA method. The results show that Chinese Sagittaria can be divided into three groups, which are composed of seven species and three varieties or forms except S. natans. Thethree groups are: group I ,with only one species S. guayanensis; group Ⅱ ,composed of S. tengtsungensis, S. wuyiensis, S. lichuanensis and Segittaria sp.; group Ⅲ, S. potamogetifolia, S. pygmaea, S. trifolia var. trifolia, S. trifolia var. sinensis, S. trifolia f. longiloba. Results of the present study are congruent with those based on morphologi-cal and karyotypical ones.

Key words: AP-PCR, Chinese Sagittaria, Molecular systematics