In the experiment we studied the effect of drugs containing nitrogen-fixing bacteria on yield of spring rape seed varieties ANIIZIS 2 different back-grounds fertilizers. Biological products were used: Rizoagrin, Mizorin, BioVays; studies were con-ducted on leached chernozyom in the zone of moderately arid forested steppe of Altai region. The study of the biologics impact on the formation of seed yield of spring rape in different backgrounds mineral nutrition in a moderately dry forested steppe of the Altai region has shown significant efficacy of their application. Drugs increase ele-ments of yield structure, photosynthetic activity of crops and yields. The yield of seeds in control was 1.67-1.85 t / hectare. While using drugs both in pure form and in the backgrounds of fertilizers, seed yield increased by 15-36 % of the absolute control. Higher yield was formed at a rate of 2.0 million pieces of seeding 1 hectare for all options and backgrounds. The increase of drugs in its pure form amounted to 15-24 %, for backgrounds NPK was 26-36 %. More important is that they were on the background N30P60K60. Therefore, increasing doses of nitrogen to 60 kg / hectare would increase production costs and is economically unreasonable. With an increase in seeding rate the increases of productivity of seeds reduce, due to the increase in plant population and a decrease in the number of pods and seeds per pod.