A new coordination polymer [Co-3(IP)(4,4'-obb)(3)](n) (1) (4,4'-obb = 4,4'-oxybisbenzoic acid, IP = 1H-imidazo[4,5-f][1,10]phenanthroline was synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR, PXRD. Single-crystal X-ray analyses revealed that [Co-3(IP)(4,4'-obb)(3)](n) was bridged by 4'4-obb ligands to form a 1D infinite chain, was further extended to 2D supramolecular structure by hydrogen bonding interactions and pi center dot center dot center dot pi interactions.