The aim of this thesis was to investigate how tractors of different masses affect soil compaction. The research included three tractors of different masses: IMT 533 weighing 1440 kg, Deutz-Fahr Agroplus 310 with attachment total weight 3630 kg and John Deere 6200 with attachment total weight 5085 kg. The research was carried out with 10 passes of the tractor over the experimental field whose soil, according to its mechanical composition, belongs to powdery loam soils. After each pass, soil compaction measurements were made using a penetrometer. The results showed that each tractor caused an increase in soil compaction with an increase in the number of passes, but that the highest soil compaction was recorded with the heaviest John Deere 6200 tractor. Up to five tractor passes, no statistically significant differences were measured compared to the initial state, and the maximum soil penetration resistance it was achieved with the tenth pass. Based on the research results, recommendations can be made for possible reduction of soil compaction by reducing the number of tractor passes and using lighter tractors where possible