Complexbilities of various ions applied in chemical analysis, had been measured and reported in the previous papers. In the present study, the complexbilities of lead and cadmium citrates were measured by the usual potentiometric compensation method, using an ion concentration cell, a quinhydrone electrode and a hydrogen electrode. The following results were obtained at 25℃ : lead citrate, K=7.81×10^ ; cadmium citrate, K=5.70×10^
