In this study, the karyo-systematic studies on the Iranian wild almond species A .communis L., A. corduchoruom Bornm., A. trichamygdalus woronow, Amygdalus lycioides Var. horrida Spach were done by the karyological methods. The meristem cells of the root tip were used for these studies. In each species, ten suitable metaphase plates were chosen and photographed so that the morphology of the chromosomes was completely obvious. The standard karyotype was prepared for the species separately and the parameters of the chromosomes, including the total length of the chromosomes, long arm, short arm, arm ratio, and centromer index, were calculated. There was a significant difference between all of the species that can be employed to recognize the species. All of the studied species were diploid, and the numbers of the chromosomes was 2n=16. The base number of the chromosomes in all of the species was X=8. In Iran, the average size of chromosomes in species of this genus was 2.42 micrometer. . Also, there was a significant difference between all of the homologous chromosomes according to the measured cytological characters. The similarity and the difference between the species were evaluated on the basis of the cytological specificities. The domestic species of A. communis L. had the most similarity with the species of Amygdalus lycioides Var. horrida Spach, and the species of A. trichamygdalus woronow and A. corduchoruom Bornm, also had the most similarity with each other. Finally, the studied species were classified into two cytologically groups.
