Electronic spectral studies of some lanthanoids [(viz. Pr(III), Nd(III), Sm(III), Eu(III), Dy(III), Er(III) and Tm(III)] in aminopolycarboxylate (viz. IMDA, NTA, HEDTA, EDTA, CDTA and DTPA) environment have been undertaken with a view to evaluate the oscillator strengths (f _JO), Judd-Ofelt parameters (τ_λ), inter-electronic repulsion Racah parameters (∂E ^k) and nephelauxetic ratios (∂E ³/∂E ¹). The parameters have been evaluated for the entirepH range (pH 2–9) with intervals of 0.5 in order to study the dependence of oscillator strengths onpH values. The extent of covalency (via parameterτ ₂) and symmetry (via parametersτ ₄ andτ ₆) in the metal-ligand interaction have been estimated with the help of τ_λ parameters. The values of oscillator strengths and Judd-Ofelt parameters have been discussed in the light of coordination number of lanthanoid metal ions, denticity and basicity of the ligands. The metal-ligand bonding pattern has been studied in the light of changes in Racah parameters and the nephelauxetic ratio. The oscillator strength values for some specific hypersensitive transitions and for the transition whereU ^λ values are significantly large have been studied as a function of ground termL andJ quantum numbers of the lanthanoids.