Galbanum ( Ferula gummosa ) is one of the most important Iranian indigenous medicinal plants with considerable number of applications in pharmaceuticals, health and cosmetics. Conservation and improvement of this plant requires basic genomic information. Chromosomal data have played an important role in the study of plant systematic, plant breeding and evolution at all levels. In the present work karyotypic evaluation for galbanum was performed and its cytotaxonomic relationships with two other plant species ( Ferula hezarlalehzarica, Doremal glabrum ) were considered. The four galbanum accessions used were collected from different geographical locations in Fereydonshahr, Isfahan, Damavan and Tafresh of Iran. To find the best treatment for breaking seed dormancy in galbanum a factorial experiment in a completely randomized design was carried with gibberellic acid (500 ppm) and placing seeds under running tap water being the main two factors. Each factor had four levels including gibberellic acid treatment of seeds for 0, 12, 24 and 48 hour and washing seeds under tap water for 0, 24, 48 and 72 hours. Seeds explants were cultured on MS medium and germination rate and percentage for each treatment was recorded. It was shown that gibberellic acid has a positive effect on seed germination and dormancy breaking in an extent that after 70 days on culture, seed germination reached a high level of 70 percent. This highly facilitated the cytogenetic studies since there were plenty of root specimens available. The result of chromosome counting demonstrated that all accessions of galbanum are diploid with 22 chromosomes (2n=22). The karyotype formula was 7m+3sm+1st for all the accessions and the average length of chromosome for Fereydonshahr, Isfahan, Damavand and Tafresh accessions were measured to be 2.178, 2.022, 2.035 and 1.880 respectively. Analysis of variance (ANOVA) results illustrated that total chromosome length and centromere index of accessions were significantly different, but the relative chromosome length was not significantly different among accessions. For instance; relative length of chromosome 1 in accession 1 was 11.70, in accession two was 11.85, in accession 3 was 12.02 and in accession four was 12.04, so this type of within species variation can be related to differences may had occurred in cell divisions stages. The result of karyotype analysis of F. hezarlalehzarica and D. glabrum showed that these two species are diploid with 22 chromosomes (2n=22) and their karyotype formula is 7m+3sm+1st. Results also demonstrated that all chromosomal traits in these plants were significantly different at the 1 percent probability level. The cluster analysis of galbanum accessions along with F. hezarlalehzarica and D. glabrum classified galbanum accessions into a separate cluster from F. hezarlalehzarica and D. glabrum that were classified in the second Karyotype symmetry parameters showed