The interaction of non - essential amino acid 2-Amino-3-(4-hydroxyphenyl) propanoic acid (2–AHPPA) and pyramidine base 2, 4-dihydroxypyrimidine (2, 4-DHP) with heavy element or heavy metal ions Hg (II) and Cd (II) have been studied in the biologically relevant conditions by potentiometric technique at silver- silver chloride electrode and at a fixed ionic strength I = 0.1M NaNO3 and 37±10C temperature in aqueous solution with the aid of SCOGS computer programme analysis. The complexation equilibria and formation constant (log ßpqrst) of biologically significant ternary and quaternary metal chelates formed by above metal-ligand interaction have been described on the basis of resulting speciation curves sketched with the help of ORIGIN 4.0.