Inhibitory interneurons play important role as the intracortical module organizing factor. The study characterized calcium binding protein expressing inhibitory intermeurons of cat's motor cortex. Nonpyramidal calbindin expressing neurons were found in layer III of area 4. On saggital sections, they were distributed along layer III in uneven manner, forming groups that lasted 400-5000 mcm. To assess neuron groups placement, a 3D reconstruction was made. It was shown that the groups were forming uninterrupted strips 400-1500 mcm in width laying in mediolateral direction inside cruciate and on superior and posterior sigmoid gyri. It seems that such groups of inhibitory intemeurons in motor cortex could create conditions to select a pool of efferent neurons and connect them in order to carry out a single physiological act.