Abstract: The relationship among 10 species and 10 cultivars in Dianthus was studied by means of Random Amplified Polymorphic DNA(RAPD)markers.Two hundred forty two polymorphic loci were amplified with 39 primers.The results of clustering analysis accorded with morphological analysis mainly.There were two clusters,species and cultivars,by clustering analysis.And the Nei(1978)genetic distance was 0.469 8 between them.Ten species could be classified into two clusters,one grew in humid grass meadow and one in dry mountanious region,and the genetic distance was 0.242 8 between them.The results showed that different environments affected the genetic distances among the ten species.