The aim of this study is the introducing of macro-emg method as electrophysiological test used in diagnosis of neuromuscular diseases. The macro motor unit potentials (macro MUPs) obtained by recording macroelectrode (modified single-fibre electrode) represents temporal and spatial summation of individual single fiber action potentials belonging to whole motor unit territory--so the uptake area is larger for macroelectrode than for the concentric electrode, commonly used in emg routine work, when central main complex is generated only from less than 15 muscle fibers [10, 12, 13]. Additional information obtained by macro-emg method is spatial organisation of muscle fibers within the motor unit, so-called fiber density (F.D) In our study macro-emg examinations were performed in 20 healthy subjects, aged 21-55, without signs and symptoms of neuromuscular disorders. Macro MUPs were recorded using special programme for macro-emg and performed on electromyograph Counterpoint. 37 muscles (20 BB and 17 RF) were examined, and median values of amplitude, area of macro MUPs and F.D. in healthy subjects of different age were analyzed. Mean values of median for amplitude and area of macro MUPs in BB and RF muscles show respectively--148 microV, 382 microV x ms, and 319 microV, 763 microV x ms. Parameters of macro MUPs obtained in healthy subjects were compared to results obtained in 10 patients with myopathy and lower motor neuron lesion. Our results have confirmed the value of macro-emg method for investigating of the pathophysiological changes in motor units in neurogenic disorders, in myopathy the study should be continued.