Karyological study of larch population members from different parts of the Larix olgensis L. Henry areal in the Primorskii krai has been carried out. The main amount of chromosomes for larch as n = 12 (2n = 24) has been confirmed. Mixoploidy was observed in all studied populations. The difference of individuals from the larch areal based on the cell amount with a different level of ploidity has been found in the population of L. olgensis locus classicus and both L. sibirica and L. gmelinii, which is probably a consequence of their hybrid nature.