The article presents the results of a study on the features on the formation of generative organs of potato (Solanum tuberosum L.) in mountainous areas of Tajikistan at a height of over 2700 meters above sea level. There is a difference in formation character of generative system of potato plants, depending on the genotype accessions. It was noted that the formation of flower buds on the total amount of from 5 to 95%, and the number of berries formed 1to 10 units /plant or from 7.7 to 20.6 % of the total number of flowers. Formation of berries of potato varieties in a little due to the amount of viable pollen grains per flower. The number of seeds in a berry varies from 51 to 150 units, and it is associated with the viability of the pollen grains of potato flower. One berry of potatoes in average contains about 96 pieces of seeds. It was determined that 16 % of potato accessions form less than 10 % have viable pollen grains, which is probably due to a partial cytoplasmic sterile pollen.