Pb(II)-1,10 phenanthroline complex was studied by Differential Pulse Polarography( DPP) in 1.0M KNO3 as supporting electrolyte at 25OC temperature. Cyclic
voltammogramme revealed that Pb (II) - nitrate behaves quasi-reversibly with EC mechanism in the supporting electrolyte. Both stepwise formation constant as well as
overall formation of the complex was followed using De Ford and Hume's procedure and overall stability constant b value of the complex was determined as 5.1474 x 1012 with complexation number of 3