SUMMARY. Cytogenetic analysis of Iris pumila L. plants from diffe-rent habitats in Ukraine revealed the intrachromoso-mal polymorphism. Chromosome number 2n = 32 was established for plants of this species. Root meristem of I. pumila seedlings of all populations showed high level of mixoploidy. The differences in the percentage of aneuploid cells and anaphase aberration were found between the sampled populations. Anaphase analysis revealed the level of chromosomal rearrangements that reached 9.2 % in some populations reached.