Abstract: In order to investigate the karyotype of Dianthus, a study was carried out on nine populations of Dianthus crinitus, D. binaludensis (an endemic species in Iran) and D. polylepis in the North-East of Iran. For present research, 8- Hydroxy quinolein 0.0002 M and aceto-orcein were used as pretreatment solution and staining. The basic chromosome number of Dianthus was X= 15. D. binaludensis and D. polylepis were diploid, while D. crinitus was found to be tetraploid. In addition, for the first time the karyotypes of the three species of Dianthus were prepared and compared with their morphological characters. D. binaludensis and D. polylepis were found to be morphologically close, with the same ploidy level but D. crinitus differs from the other species by in that it is tetraploid suffruticous in habit, has white petals and a membranous herbaceous stigma with nerves.