A new 3D lanthanide metal-organic framework, [Sm(L)(Bpdc)(0.5)(Phen)](a) (I) (L = 4,4'-bis(2-sulfonatostyryl)biphenyl; Bpdc = 4,4'-biphenyldicarboxylate; Phen = 1,10-phenanthroline), has been synthesized hydrothermally and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis and single-crystal X-ray diffraction (CIF file CCDC no. 990856). Compound I crystallizes in monoclinic, space group P2(1)/n with a = 13.070(3), b = 21.365(4), c = 14.947(3) , beta = 101.65(3)A degrees, V = 4087.8(15) (3), rho (c) = 1.572 g/cm(3), Z = 4, mu = 1.597 mm(-1), F(000) = 1944, and the final R = 0.0573 and wR = 0.1238 for 9304 observed reflections (I > 2 sigma(I)). It is evident that there is a face-to-face pi-pi stacking interaction between each L ligand with adjacent Phen groups at a plane-plane distance of 3.482 . The ring normal and the vector between the ring centroids form an angle of 11.6A degrees up to centroid-centroid distances of 3.555 . The experimental result shows that compound I exhibits good thermal stability and luminescent property.