The article gives an analysis of the influence of variety, self-pollination, cross-pollination on the seed yield components in bird’s-foot trefoil (Lotus corniculatus L.).The test results are designed for further planning of breeding work with this crop and finding sources of self-compatibility.The research was carried out in 2019, in the breeding greenhouse of the Federal Williams Research Center of Forage Production and Agroecology.We organized greenhouse experiment. Plants were grown in 3 l vessels. Soil fertility and acidity were moderate. 40 genotypes of varieties Smolenskiy 1 (Smolensk State Agricultural Experimental Station named after A.N. Engelhardt) and Izis (Research and Practical Center of National Academy of Sciences of the Republic of Belarus for Arable Farming) were analyzed. After self-pollination of flowers, the infructescense decreased by more than 15 times, the number, weight, and plumpness of seeds, decreased by more than 30 times.The average number of seeds in a bean decreased by 2 times. The average weight of 1 seed decreased by 8.5%. The average bean length decreased by 0.7 cm. The difference between plumpness of seeds from Izis genotypes and Smolensky 1 genotypes after self-pollination is statistically significant. No genotypes with high self-compatibility were found. It is necessary to continue the search for this hereditary feature among genotypes of various eco-geographical origin. To create inbred lines, it is necessary to increase the number of self-pollinated flowers. To facilitate the manual pollination of the flowers of bird’s-foot trefoil, a technique should be developed.