Cholinergic innervation of the neocortex is important for normal cognitive functions such as learning and memory. The present work was undertaken to study the influence of carbachol, atropine and hexamethonium on the evoked and background impulse neurons activity of the motor cortex of cat during operant reflex. Experiments were carried out on adult awake cats. The impulse activity of 40 isolated cortical neurons was recorded extracellular with a glass micropipette. One of the barrels was filled with 4.0 M NaCl, other for the iontophoresis with: carbachol, atropine or hexamethonium. The agonist of cholinergic receptors, carbachol, increased the background impulse activity of neurons on 51% and the evoked activity related on 52%. Application of atropine and hexamethonium, antagonists of the m-and n-cholinergic receptors, respectively, the number of spikes related to the placing reaction decreased on 42% in the case of atropine and on 23% in the case of hexamethonium. The frequency of the background activity decreased on 31% and on 23% while applying atropine and hexamethonium, correspondingly. It was suggested, that endogenous acetylcholine, in natural conditions, takes part in the maintenance of a level of background neurons activity of motor cortex and in the maintenance of process of formation of motor commands. The obtained effects mostly depend on the functions of m-cholinergic receptors.