In this paper the problem of an experimental research of the adhesive strength of the coating during plasma spraying combined with the activation of spraid surfaces by the arc discharge of low pressure applied to the products of mechanical engineering and electrovacuum devices. The characteristic of plasma coatings is their relatively low strength. For strength increasing of the coating it is offered to equip the traditional circuit of plasma spraying with the additional gas category which is intended for activation of a surface of spraying. The pulse arc discharge of low pressure is used as such discharge. The experiments on research of the adhesive strength of the coating were carried out on the samples of the cylindrical form in diameter of 10 mm and length of 40 mm from such materials as Mo, Ni, Сu, and also with the powders of W, Ti, Mo. Argon was used as plasma generated, transporting and protective gas. The activation of a pulsed arc discharge can be performed with a large number of combinations of values of the parameters of the gas discharge. Table 1 shows the results of the comparative data of the adhesive strength of the coating with different methods of activation of spraid surface. Tab. 1. The comparative datatableThe results of the researches allow to draw the following conclusions. The use of continuous lowpressure arc discharge for surface activation of the workpieces in plasma spraying process produces a high adhesion strength of the coatings (60…90 MPa). However, when the current arc-discharge is to about 90 A the workpiece is heated to a high temperature, and when the discharge current decreases the efficiency of the process is essentially reduced. The high adhesive strength of the covering (60…90 МПа) and productivity of spraying process at rather low temperature of heating of a workpiece (200… 40000С) may be obtained by the use of the pulse arc discharge of low pressure for activating of the spraid surface. This work was supported by the program "M.Y.S.I.C" (U.M.N.I.K) on 2012.