The paper presents the research results concerning the impact of working speed, changed every 2 km∙h-1 within the scope from 6 to 14 km∙h-1 on the irregularity of seeding depth of Fregata winter wheat at the variant use of two basic elements of cultivation-sowing aggregate (universal seeder SO43/3C - 1 "Poznaniak 6" and cultivation aggregate AS30 of AGRO-MASZ company). In the I variant - cultivation-sowing treatment was carried out in two separate stages: soil cultivation and wheat seeding. Whereas in the II variant - soil cultivation treatment and seeding was carried out simultaneously. The statistical analysis which was carried out (analysis of variance) shows that working speed of sowing and cultivation-sowing aggregates has significant impact (α=0.05) on the depth of seeding wheat carried out in two variants (combined - I variant and separate - II variant), the application of the cultivation and seeding unit. Average values of sowing depth, obtained in both variants of the experiment was by approx. 15 and 6 % (respectively variant I and II) higher than the set sowing depth (3 cm) and was respectively 3.44 and 3.19 cm.