Mixed ligand stability constants of Co(II),Ni(II),Cu(II) and Zn(II) complexes with enalapril drugs (LP) and Glycine (LS) have been determined pH metrically at room temperature and 0.01 M ionic Strength (NaClO4) in aqueous solution. The formation of various possible species has been evaluated by computer program and discussed in terms of various relative stability parameters. The ternary complexes shows, stability order as Δlogk = 1:1:1 Co(II)>Ni (II)>Cu(II))>Zn(II) 1:1:2 Ni(II)~ Zn(II)>Co(II)>Cu(II)