It is a known fact that Pb electrode is severely corroded in the presence of Cl ion.Now, two-component alloys such as Pb-Ag or three-component alloys consisted of Pb-Ag added with Sb, Sn, etc., showed a remarkable corrosion resistant behavior as compared with simple Pb electrode in artificial sea-water.For the purpose of studying this phenomenon, it was examined the current-voltage curve of Pb, Pb-Ag, etc., in the solution of 0.5N-Na2SO4, 0.5N-NaCl and artificial sea-water.The results obtained are as follows:(1) In 0.5N-Na2SO4 solution, Pb-Ag, Pb-Ag-Sb and Pb-Ag-Sn electrode showed a similar curve as Pt electrode but oxygen evolution voltage was 1.15V referred to S. C. E. Oxygen evolution voltage of Pb was greater than Pb-Ag electrode.(2) In 0.5N-NaCl solution, the chlorine evoluting voltage of Pb-Ag electrode was greater than Pb electrode.Ag and Sn did not show a remarkable passive phenomenon in the current-voltage curve.(3) In artificial sea-water, Pb electrode showed almost the same current-voltage curve as Pb-Ag electrode.In the detailed analysis of those curves, it was confirmed that at the Pb electrode, the electric current is produced by chlorine evolution, and at the Pb-Ag electrode, it is produced by the oxygen evolution.