A new 2D barium-organic framework, [Ba2（Hbidc）2]n （1, Hbidc = 1H-benzimida- zole-5,6-dicarboxylate）, has been solvothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, TGA, powder X-ray diffraction, and single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group Pī with α= 6.8785（14）, b = 9.4558（19）, c = 14.641（3） A, α = 86.22（3）, β = 82.27（3）, γ = 88.40（3）°, V = 941.4（3） A^3, Z = 2, Mr = 682.96, Dc = 2.409 g/cm^3, μ（MoKα） = 4.217 mm^-1, F（000） = 640, the final R = 0.0587 and wR = 0.1619 for 3030 observed reflections with I 〉 2σ（I）. Structural determination reveals that 1 exhibits an interesting 2D layer structure constructed by carboxylate groups of Hbidc ligands and shows good thermal stability （up to 400 ℃）. Solid-state 1 emits intense indigotin photoluminescence with fluorescence lifetime of 62.13 （408 nm） at room temperature. The H3bidc ligand and its barium complex have been screened for antibacterial activity against several bacteria strains, and the results are compared with the activity of penicillin.
