Cynodon dactylon is a perennial herb which has economical and industrial importance and widely used as warm-season turf and forage grass in the temperate and tropical regions. The taxonomic and cytological status of this species is not well documented. In this study, the cytological characteristics of 10 samples collected from different regions of Iran were analysed. Two ploidy levels: tri and tetraploid were counted from the root tips as 2n=3x=27 and 2n=4x=36 with a basic chromosome number of x=9. The karyotypes and the chromosomal parameters showed a nearly symmetrical karyotypes. The presence of triploid populations indicated that the probable existence of the diploid populations in this region hybridized with tetraploid individuals in the past to produce triploids that subsequently stabilized by vegetative reproduction (rhizome).