AbstractRubus hyrcanus is considered as an important wild blackberry species scattered around the Caspian Sea. In this research, ISSR and morphological markers were used to assess genetic diversity in several populations of R. hyrcanus from various geographical regions of Caspian Sea in Iran. Twenty-five populations of R. hyrcanus from three regions (North- Western (NW), North- Eastern (NE) and Central (C)) and one population from R. discolor were applied in this research. Ten primers were used to amplify bands out of which 157 (77.13%) were polymorphic. Cluster and Principle coordinate analyses (PCoA) showed the higher similarity of NE and NW populations. Analysis of molecular variance (AMOVA) revealed that the differences among three collection regions only accounted for 28.09% of the total variation, whereas differences among populations within groups were 66.03%. Analyses among three regions showed that the minimum gene diversity over loci was observed in NW (0.16) and NE (0.17), while the highest one was found in C (0.238) region. Furthermore, narrow genetic base and relatively high genetic differentiation obtained for studied R. hyrcanus genotypes. The results of morphological analysis in most cases corresponded to those obtained through molecular analyses.