The purpose of this research was to study the morphophysiological and biochemical parameters of flax seeds after accelerated aging (AA) test, which allow haracterization of storage potential (SP) of collective accessions in active collections of the gene bank with the purpose of their ex situ conservation, and to reveal genotypic differences of genotypes by this trait. Flax genotypes should be grouped by their potential capability to preserve viability of samples exposed to high temperature and humidity. Specify the necessity to restore viability of accessions. Objects of our studies were collection accessions of flax (fam. Linaceae, genus Linum, species Linum usitatissimum L.) from active collection of the gene bank. SP of seeds was determined by two tests: test for accelerated aging of seeds by Hampton and TeKrony’s method and test for electrical conductivity (EC) of solutions, both are included in the International Rules for Seed Testing. AA-test of flax seeds was conducted under the increased air temperature (42-43оC), air humidity (90-100%), aging time was 72 hours. After this test, various morphophysiological parameters of seeds and seedlings were measured according to the International Rules of ISTA: germinating power, and germinability of seeds, radicle length, fresh and dry biomass of radicles. Electrical conductivity of solutions with normal and aged seeds was measured by conductometer. With regard to biochemical parameters, the activity of the peroxidase enzyme was measured in radicles of seedlings. Data were processed using the software Statistica 7. According to the set of different parameters of flax seeds after the AA of seeds, the following flax genotypes had the highest storage potential: Vizit, Batist, Argentina, and the middle SP was found in Belinca. Polesskiy 6 and Kaufmann. Conclusions: 1. Use of accelerated aging test of seeds and determination of their morphophysiological and biochemical parameters allowed assessment of storage potential of flax collection accessions from the active collection of the gene bank. 2. Significant positive correlation of germinability of flax seeds with germinating power, radicle length, fresh and dry biomass of seedlings was revealed after conduction of test for accelerated aging of seeds.