Operational properties, classification and layout diagrams, as well as the basics of the theory of tractors and agricultural vehicles are considered: the work of the driven, driving wheel and caterpillar mover, traction and energy balances, traction and braking dynamics, cross-country ability, stability, controllability, smoothness, methods of experimental evaluation of traction indicators. The textbook describes methods for reducing dynamic loads in tractors and cars and ways to reduce the harmful effects of propulsors on the soil, as well as methods for increasing the energy and agrotechnical properties of tractors. Automatic devices used in agricultural tractors of domestic and foreign production and ways of improving their operational properties are considered.