To identify intergeneric, interspecific, and intraspecific polymorphisms, PCR-RFLP studies of the chloroplast rbcL gene profiles were carried out using five restriction endonucleases (AluI, HpaII, BsuRI, BstHHI, BstMBI) in 14 species belonging to 6 different genera and 7 Thuja occidentalis cultivars. For all the genera studied (Pinus sp., Abies sp., Picea sp., Microbiota sp., Syringa sp., Thuja sp.), A genus-specific restriction profile characterized by a unique combination of restriction DNA fragments was revealed. The combination of enzymes used in the study did not reveal the interspecies and intraspecific variability of the rbcL gene. Species belonging to the same genus and all varieties of western thuja were characterized by identical PCR-RFLP profiles. It is assumed that further research, with the inclusion of a larger number of species and enzymes, will reveal polymorphism at the interspecies and intraspecific levels.