The mineral composition of Allium cepa L. leaves was measured by using the scanning electron microscope of Japanese company JEOL, model JSM600LA with EDS system. 11collection samples of FRC “All-Russian Institute of Plants Genetic Resources named after N. I. Vavilov” and 4 samples of FSBSI “Research Institute of Agriculture of the Crimea” were studied. 12 main elements (in mass., %) contained in onion leaves were evaluated. The samples with the maximum macro- and micronutrient elements accumulation in the leaves used for the sourthern subspecies breeds and hybrids selection were revealed. These samples can be used to prevent the elements deficiency in the human body. The following samples number with a high accumulation of the elements in the leaves was revealed: K – nine (from 20.0 to 3.3 max %: B12132B, trimontzium, Rouge pale, Red Wetherstfield, Blood red flat, Valensiya, Tavricheskiy, Yaltinskiy lux, Yaltinskiy rubin), P – five (from 1.8 to 2.8 mass., %:B12132B, Mestniy, Valensiya, Yaltinskiy lux, Yaltinskiy rubin), Mg – one (2.23 mass., %: Rouge pale), Ca – nine (from 5.4 to 8.3 mass., %: Mestniy, Rouge pale, Mestniy, Red Wetherstfield, Blood red flat, Valensiya, Brown Beauty, Yaltinskiy lux and Yaltinskiy rubin), Fe – two (from 0.5 to 0.8 mass., %: B12132B, Tavricheskiy), S – seven (from 2.2 to 2.5 mass., %: B12132B, Mestniy, Red Wetherstfield, Tavricheskiy, Yaltinskiy lux, Yaltinskiy rubin, Yaltinskiy model No. 3), Na – two (from 1.3 to 1.5 mass., %: B12132B, Mestniy), Cl – five (from 4.0 to 7.0 mass., %: Mestniy, B12132B, Trimontzium, Red Wetherstfield, Yaltinskiy model No. 3), Cu – one (1.9 mass., %: Yaltinskiy model No. 5), Mo – eight (from 5.2 to 7.0 mass., %: Tavricheskiy, Yaltinskiy lux, Yaltinskiy rubin, Yaltinskiy model No. 3, Mestniy, Trimontzium, Red Wetherstfield, and B12132B), Zn – seven (from 0.5 to 4.97 mass., %: Yaltinskii model No. 3, Mestniy, B12132B, Rouge pale, Blood red flat, Brown Beauty, Yaltinskiy rubin) and Si – one (0.5 mass.%,%: Yaltinskiy lux). The order of the elements accumulation variation in the onion samples was distributed as follows: Zn > Fe > Si > Na > P > Cl > Mo > Mg > S > Ca > Cu > K.