Abstract:RAPD analysis was applied to the major species in the section Tacahamac of the genus Populus,such as P.suaveolens Fisch.,P.ussuriensis Kom.,P.Koreana Rehd.and P.maximowiczii Henry in order to assess the degree of genetic variability between and within these species.Most of the amplification products generated from the four species using the seven primers are monomorphic,but three out of the 7 tested appeared to produce a considerabledegree of polymorphism at the interspecific level and all the tested primers could produce varying extent of polymorphism at the interspecific level within all the four species.A dendrogram displaying hierarchial associations was generated using NT-SYS computer programme and more apparently revealed genetic variability between and within the four species.The result is of significance to the future improvement of these species.In addition,the resulting analysis was in broad agreement with previous classification of the species studied,confirming the validity of the method. The results showed that P.Koreana Rehd.appear as the closest relative of P.suaveolens Fish.,followed by P.ussuriensis Kom. and further away, P.maximowiczii Henry.questioning the current classification, in which P.suaveolens Fisch.and P.ussuriensis Kom.share the closest relationship among the species in the section Tacqhamac.