Muscle contraction mechanism is presently considered on the level of interaction between actin and myosin. The specific arrangement of these proteins within the muscle sarcomere has not been, however, taken into account. Computer reconstruction of the 3D structure of the vertebrate striated muscle sarcomere has allowed to solve a number of controversial aspects. That concerns such aspects as: the manner of myosin molecules packing within thick filament, the way of the myosin cross-bridge action, and the role of thin filament in contraction.