This paper reports the determination of stability constants for complexes of Pb(Ⅱ) with Gly,Ala, Asp and Gly-Gly using both micro-pH-metric titrations and the application of convolution-de-convolution cyclic voltammetry at 25℃ and I = 0.10 mol.dm~(-3)(KNO_3). Stability constants werecalculated from pH-metric data using the SUPERQUAD computer program and cyclic voltammogramswere collected, stored and manipulated using the E G and G CONDECON 300 software. A consider-ably larger ligand: metal ratio (e.g. 50:1) was possible using voltammetry. Under these conditions,hydroxy complex formation was minimised and the formation of bis-complexes optimised. Computerbased calculations were carried out on PC-compatible microcomputers fitted with mathematics co-processors. Evaluation of results from the two techniques suggests that stability constants for thespecies [PbL_2] are reliable when calculated from voltammetry while those for [PbL] are mote reliablewhen determined by pH-metric titration. This paper reports the determination of stability constants for complexes of Pb (II) with Gly, Ala, Asp and Gly-Gly using both micro-pH-metric titrations and the application of convolution-de- convolution cyclic voltammetry at 25 ° C and I = 0.10 mol.dm ~ (-3) (KNO_3). Stability constants werecalculated from pH-metric data using the SUPERQUAD computer program and cyclic voltammograms collected, stored and manipulated using the EG and G CONDECON 300 software. A consider-ably larger ligand: Under these conditions, hydroxy complex formation was minimized and the formation of bis-complexes optimized. Computerized analog were carried out on PC-compatible microcomputers fitted with mathematics co-processors. Evaluation of results from the two solutions suggests that stability constants for the specs [PbL_2] are reliable when calculated from voltammetry while those for [PbL] are mote reliable determination by pH-metric titration.