AbstractRAPD was employed to assess the genetic variation among Eriochei r sinensis populations of the Yangtze , Liaohe and Oujiang river systems. 31 random reproducible primers revealed 121 amplified fragments in which 27 were polymorphic. Intraspecific genetic variation was low ( D = 01004～01063) . Intrapopulation genetic variation of Liaohe population and Oujiang population were higher than that of Yangtze population while the interpopulation variation between Liaohe and Oujiang populations was lower than that between either of them and Yangtze population. The results suggest that the human economic activities have probably caused gene exchanges between the two populations.