The investigation of t.he optical space-time-structure of the discharge development was made for various values of p D (1,3 kPacm, 33,4 kPacm) by means of the variation of the electrode distance for two gas pressures. The broadening of the bistable region with growing electrode distance can be explained by the effect of the positive space charge as a virtual anode. Thus the spnce charge memory is dependent on the value of pD. If the space charge breakdown takes place, i t light front moves from the anode to the cathode, its velocity, wrying from 3 . 10' cm/s to X . lo5 cm/s. I n the volume an optical structure develops which is analogous to that of a medium pressure glow discharge. If the time between successive discharge pulses is too short, then the decay of the positive space charge is incomplete and t h e is no Townsend phase. The process tlrpends ,via the ion drift velocity, on the electrode distance.