A complex [Sm(2-IBA)2(2,2'-bipy)(NO3)]2 (2-HIBA=2-idobenzoic acid; 2,2'-bipy=2,2'-bipyridine) was synthesized by solvent method and characterized by X-ray single-crystal diffraction. The complex crystallized in triclinic crystal system, Pi space group, with a=0.97873(3) nm, b=1.28124(3) nm, c=1.29174(3) nm, α=108.3740(10)°, β=111.7340(10)°, γ=101.7870(10)°. The complex was the centrosymmetric binuclear molecule, in which two Sm3+ ions were connected by four 2-IBA ligands. Two of the 2-IBA ligands were in a bidentate bridging mode and the other two were in a tridentate bridging mode. Sm3+ ion was also coordinated to one chelating NO3- group and one 2,2'-bipy molecule. The 2D supramolecular network formed through weak I...I interactions and π...π stacking interactions. The fluorescent emission peaks at 562, 595, and 642 nm corresponded to the 4G5/2→6F5/2, 4G5/2→6F7/2, and 4G5/2→6F9/2 transitions of Sm3+ ion, respectively.