A new manganese coordination polymer (CP) has been synthesized under hydrothermal conditions. It’s formula is {Mn₂(Oaobtc)(bpe)(H₂O)₄]}_n, where H₄Oobtc represents oxide azobenzene 2,2΄,3,3΄-tetracarboxyl acid, and bpe is 1,2-bis(4-pyridine) ethylene. It was characterized by elemental analysis, infrared spectrum and X-ray single-crystal diffraction. The coordination polymer crystallizes in the monoclinic system, space group P2₁/c. The central ion was coordinated with H₄Oobtc ligands using bridging model, and carboxylic group connects two adjacent Mn(II) ions into dimer units. The oxygen from carboxylates connect these dimer units into a one-dimensional (1D) chain, and N atoms from the bpe further expanded them into three-dimensional (3D) supramolecular edifice, eventually. Variable-temperature magnetic measurements of CP 1 indicate the presence of weak antiferromagnetic exchange between two nearest Mn(II) ions with J = –0.367 cm^-1.