Hardware and software system, which makes it possible to visualize the glow center, marker of the excitation center in tissue, in the electric field, is created. The system was tested in 14 experiments with sinoatrial nodes of cat's hearts, which's fist excitation's center is in the depth of the right auricle's myocardium, and in 30 experiments with frog's venous sinuses, which's first excitation's center is situated in the superficial layer of the sinus wall. Also observations were held with deeply situated center - in cat's tooth's pulp, which is surrounded by insulators: dentine and tooth's enamel. The ability of visualization the excitation's center was developed at localizations in different depths