A study of the water content in autumn revealed a significant 1.7-2.9-fold increase in the ratio of bound and free water in plum genotypes in November compared with September. At the same time, a significant increase in the content of sugars amount (by 9.9 % and 10.8 %) was noted in the bark of annual shoots n the plants of Prunus salicina and Prunus × rossica Erem. The outcome obtained suggest that the varieties of Prunus × rossica Erem. – Vetraz, Gek, Zlato Skifov, Kubanskaya Kometa and Prunus salicina – Nezhenka, Orlovskaya Mechta, Skoroplodnaya, Suvenir Vostoka and ELS 18476 have greater frost resistance in winter, because their adaptive processes were more intense in autumn.