Beans (Phaseoulus vulgaris) is a plant species very important for human consumption. In Serbia, it is grown on relatively small areas andwith low yields. Beans have agrotechnical significance, because they live in symbiosis with bacteria that fix nitrogen, and are suitable for sustainable production. The aim of this study was to determine the significance of the application of a microbiological preparation on the basic parameters of soil biogenicity and protein content in beans of Max and Belko varieties. The total number of bacteria was increased by 47.25% and the number of Azotobacter by 102.86%. The protein content in the grain, on average for both varieties, was increased by 3.94%. It can be concluded that the use of microbiological preparations should be part of the mandatory agrotechnical measures.