In forestry at gathering timber is used diffrerent types of tyres. In this thesis we made morphological analysis of tyres for heavy machinery, adapted agricultural ractors and forwarders. We studied the technical characteristics of the tyres in both groups. For the analysis were selected 7 different companies producing tractor tyres, Alliance, BF Goodrich, Firestone, Michelin, Nokian Heavy Tyres, Pirelli and Trelleborg. Parameters which are discussed in this thesis are the width of the tyre, tyre diameter, static loaded radius, load index, inflation pressure, the maximum permissible load, deformation of the tyre. We found different dependencies between these parameters. It was found, that the higher the permissible inflation pressure is, the bigger is the load on the tyre. With the width of the tyre inflation pressure increases. For work on poor-carrying soils are more suitable wide erformance of tyres. The width of the tyre with the tyre diameter increases. Maximum load of the tyre increases with the width of the tyre. Larger than thediameter of the tyre is, the greater is the deformation of the tyre. More than the vehicle speed increases, the lower is the maximum load of the tyre. During the load index from collected data, and the load index of a standard, is no specific differences. Greater than a maximum load of the tyre is, the greater is the load index.