[en] Two dimeric rare-earth complexes [Eu(o-MOBA)₃phen]₂.2H₂O (1), [Tb(o-MOBA)₃phen]₂.2H₂O (2), (where o-MOBA = o-methoxybenzoate, phen 1,10-phenanthroline) were synthesized and structurally characterized. Both of them consist of neutral dimeric molecules, crystallize in triclinic system, space group P1-bar. Each RE(III) ion is nine-coordinated with one 1,10-phenanthroline molecule, one bidentate chelating carboxylate group, two bidentate bridging carboxylate groups and two tridentate bridging carboxylate groups. Complex 1 shows bright red luminescence, 2 shows green luminescence under UV light at room temperature, respectively. The thermal analysis indicates that they are all quite stable to heat