The basis of the theory of dynamic processes in small tools and equipment are stated in the work. The considered machines are classified according to dynamic features. There are determined parameters of motion and dynamic loading with taking into account the law of change of the reduced moment of inertia of a drive, resistance on working body and the mechanical characteristic of the engine at typical modes of operation.The method of calculation of optimal meaning of reduced moment of inertia of moving parts and reduced stiffness by criteria of a minimality of velocity fluctuation and dynamic factor developed by the authors is given.The book is intended for scientific and engineering workers of the research, design and engineering organisations and factories, involved in research, designing, calculation and manufacture of the motorised small tools and equipment. It can be also useful for students and doctorants of the departments of mechanisation of agricultural higher education institutes.