Using a thin platinum anode in contact with an electrolytic solution, normal electrolysis develops spontaneously to contact glow discharge electrolysis (CGDE) at sufficiently high voltage. During this transition, midpoint voltage (V(D)) is an important critical value. From V(D) on, plasma is sustained by direct current glow discharge between the electrode and the electrolyte surface. And H(2)O(2) is the main non-faradaic yield. In this study, effects of conductivity on V(D) and the concentration of H(2)O(2) have been investigated in Na(2)SO(4) and NaCl solution. The results indicate that V(D) decreases with the increasing conductivity. And the value of V(D) and the concentration of H(2)O(2) in NaCl solution are less than those in Na(2)SO(4) solution. The concentration of H(2)O(2) increases steadily and then decreases to maintain a stationary value.