The absorption and luminescence spectra of the solid compound Eu([C(CH3)(OH)(PO3H2)(PO3H)] [C(CH3)(OH-(PO3H)(2)]) (also written as Eu(H3L)(H2L)) are measured by dispersing the microcrystalline complex in a silicone film. Nine free ion levels and eight crystal field levels are identified. A set of 20 free ion parameters for Eu3+ is optimized. The crystal field levels are calculated using these optimized free ion levels combined with a set of crystal field parameters for the analogous Er3+ complex assuming a C( 2v )site symmetry. The experimental crystal field levels are in good agreement with the calculated levels. This means that the; site symmetry of both lanthanide ions in this complex can be described by a C(2v )point symmetry. In acidic (pH < 2) solutions in 2 M NaNO3 medium, Eu3+ and 1-hydroxyethane-1,1-diphosphonic acid (HEDP) form several complexes. By measuring the overall absorption spectra of Eu(3+ )and HEDP as function of the ratio Eu3+/HEDP and at different pH values, the absorption spectra of the Eu(H3L)(2+), EuCH3L)(2)(+), and Eu(H3L)(2)(H2L)(-) complexes are deduced. By analysis of the shape of the hypersensitive transition, D-5(2 <--) C F-7(0), and the intensities of all the electric dipole transitions of the Eu3+ ion, it was found that the site symmetry of the Eu3+ ion in the Eu(H3L)(2)(H2L)(-) complex is similar to the site symmetry of the Eu3+ in the neutral Eu(H3L)(H2L) solid complex. The site symmetry of the Eu3+ ion in the Eu(H3L)2+ and in the Eu(H3L)(2)(+) complexes was found to be similar to the site symmetry of the free Eu(3+ )in 2 M NaNO3 solution.