The article presents the results of a study of the antioxidant complex in the fruits of 11 plum varieties growing in the Sverdlovsk region, including 6 varieties of Ussuri plum (Prunus ussuriensis) and 5 varieties of blackthorn (Prunus insititia). As a result of studies of antioxidant indicators, the values of antioxidant activity were, mmol / dm3 eq, in blackthorn from 21.748±0.652 to 52.404±1.572 (highest value in the variety "Iset", the lowest value in the variety "Sergo"); in the plum of Ussuri from 4.713±0.141 to 23.993±0.720 (highest value in the variety "Iset", the lowest value in the variety "Sergo"); in the plum of Ussuri from 4.713±0.141 to 23.993±0.720 (highest value in the variety "Dostoynaya", the smallest in the variety "Uralsky Zori"); especially it is possible to highlight the promising form of thorns "23-15" with a value of 81.220±2.437. At the same time, the content of flavonoids was, mg / 100 g of the edible part, in blackthorn from 333.968±10.019 to 504.729±15.142; in Ussuri plum from 72.374±2.171 to 368.442±11.053. The highest value of this indicator is 647.235±19.417 mg/100 g in the perspective form of blackthorn "23-15".