A one-dimensional chain coordination polymer [Co(II)(C_6H_5CH=CHCOOH)_2(4,4′- bipy)(H_2O)_5]n has been synthesized with cinnamylic acid, 4,4′-bipy and cobaltous chloride as raw materials. Crystal data for this complex: monoclinic, space group P21/c, a = 1.1481(3), b = 1.1230(2), c = 1.1759(3) nm, β = 97.054(4)o, V = 1.5046(6) nm~3, Mr= 617.50, Dc = 1.363 g/cm~3, Z = 2, μ(MoKα) = 0.627 mm~(-1), F(000) = 646, S = 1.062, R 0.0443 and wR = 0.1178. The crystal structure shows that two neighboring cobalt(II) ions are linked together by one 4,4′...