The metal-organic frameworks of the formula Ln(bta)ÁnH 2 O where n = 3, 4, 5 or 6; bta = benzene-1,3,5triacetate ion: [C 9 H 9 (COO) 3 ] 3-; Ln = La(III), Nd(III), Eu(III), Tb(III), Ho(III), Tm(III), Lu(III) were synthesized by the reaction of LnCl 3 ÁxH 2 O with ammonium salt of H 3 bta acid in water solution. Insoluble water compounds crystallize in the monoclinic or triclinic crystal system, and they are stable up to 30°C. When heated, they decompose up to 160-200°C in two stages to stable anhydrous compounds. The dehydrated compounds Ln(bta) are still crystalline and stable up to about 350°C. When heated above 350°C, they undergo decomposition where the intermediate products are Ln 2 O 2 CO 3 or Tb 4 O 6 CO 3 and the residues are: Ln 2 O 3 or Tb 4 O 7. The interpretation of IR spectra of title compounds was made taking into consideration the experimental and theoretical wavenumbers obtained for H 3 bta specie. The XPS spectra of H 3 bta and its complexes were recorded. The way of metal-carboxylate group of ligand coordination was discussed. This work presents the results of the XPS analyses, which allowed to determine the binding energies (E b) for the main lines of Ln3d, Ln4d, Ln5p, C1s, O1s spectra, spin-orbital splitting and full width at half maximum complexes.