The electroless copper deposition rate for 6 Cu-II complexes decreases in the ligand sequence: nitrilotriacetic acid (NTA) > N,N,N',N'-tetrakis-(2-hydroxypropyl)-ethylenediamine (Quadrol) > glycerol > L(+)-tartrate similar to sucrose > DL((-)(+))-tartrate. Both Cu-II complex stability and specific ligand effects were found to influence the Cu deposition process. The specific ligand effects are most obvious in the case of Quadrol (high kinetic activity at a high Cu-II complex stability), glycerol and sucrose (additional reaction of Cu2O formation by interaction of Cu-II with ligand). According to the EQCM data for 11 Cu-II complexes (including data from the former study) the higher kinetic activity is demonstrated by complexes with ligands containing amino groups; this factor is more important for Cu deposition rate than copper complex stability. A potential dependence of the Cu reduction partial current on the electrode potential has been extracted from the EQCM data in the complete electroless plating bath. An increase in Cu-II reduction rate was found to occur in electroless plating solution for Cu-II complexes with NTA and Quadrol compared with that in formaldehyde-free solutions. Possible reasons for the acceleration of the partial Cu-II reduction reaction and the overall process kinetics are discussed using a hypothetical reaction sequence involving intermediate copper oxy-species and active Cu* formation as well as development of the preferred Cu surface structure.