The passage of the current under industrial frequency (the voltage 12 kV) trough dielectrical tubes filled with electrolyte solutions cause the formation of plasma structures, involving up to tree simultaneously existing plasmoids. Their appearance may be as cylinder with the length up to four diameters of the tube, disk or ring. This structures move along tubes, as a rule, in the direction of the solution movement, and their lifetime is up to 0.2 s. The discharge current in the period of plasmoid existence is the sequences of pulses with the mentioned above duration, modulated with the frequency of 50 Hz. This type of plasma-solution system is characterized by high efficiency of modification action at highmolecular compounds.