Methods of modeling the processes of interaction of forest machines with the subject of labor and the external environment are considered ; the general principles of dynamically equivalent schemes and equations of dynamics are given ; models for the study of dynamic loads in elastic bonds of forest machines in the main loading modes are given ; methods of modeling the activities of operators on the use of technical speeds of elements of technological equipment are described. Theoretical conditions, methods of calculation are illustrated by numerical examples and solutions on computers. ;Griff:Recommended by the State Committee of the Russian Federation for Higher Education as a textbook for students of universities studying in the specialty "Machines and equipment of the forest complex"