Abstract: The solid complex of N-(o-hydroxybenzyl)-glycine (HBG) with copper ( Ⅱ )-Ctt(HL)₂ was prepared under acidic conditions and characterized by solubility, molar conductance, magnetic moment, infrared spectra and thermogravimetric studies. The results indicate that two amino nitrogen atoms and two carboxylic oxygen atoms in HBGare coordinated in the complex. The formation constants of Cu( Ⅱ )-HBGcomplexes (K^Cu_HLCu, K^Cu_Cu(HL)2,β^Cu_CuL(HL) , β^Cu_Cu(HL)2 , K^Cu_CuL , β^Cu_CuL2), the proton dissociation constants of Cu(HL)₂ (K^H_CuL(HL)x, K^H_CuL(HL)) and the hydrolysis constant of CuL(H₂O)(K^H_CuL(H2O)) in aqueous solutions were determined pH-metrically at 30.0 ± 0.1 ℃ in the presence of 0.10M KNO₃. The variant coordination forms of HBGin the complexes is discussed.