Two single and double chain manganese coordination polymers [Mn(L1)(H2O)(2)]NO3}(n) (1) and [Mn(L2)(2)(H2O)](n)(2) (HL1 = 2,2 ': 6',2 ''-terpyridine-4 ''-carboxylic acid, HL2 = 4'-(4-carboxyphenyl)-2,2':6',2 ''-terpyridine) have been synthesized hydrothermally, and characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. Compound 1 crystallizes in monoclinic space group P2/c, while 2 crystallizes in triclinic, space group P (1) over bar. Crystal data for 1: C16K14MnN4O7, M-r = 429.25, a= 10.684(2), b = 9.338(1), c = 9.896(2) angstrom,beta = 113.89(3)degrees , V = 902.7(3)angstrom(3) , Z = 2, T = 153(2) K, D-c = 1.579 g/cm(3), mu = 0.780 mm(-1), F(000) = 438, R = 0.1084, wR = 0.3507, and GOF = 1.069; For 2: C44H30 MnN6O5, M-r = 777.68, a = 11.255(2), b = 11.554(2), c = 15.417(3) angstrom, alpha = 107.28(3), beta = 101.07(3), gamma = 107.23(3)degrees, V = 1740.2(6) A(3), Z = 2, T = 293(2) K, D-c = 1.484 g/cm(3), mu = 0.440 mm(1), F(000) = 802, R = 0.0471, wR = 0.1050, and GOF = 0.948. In both compounds, the central Mn(II) ions adopt the same distorted pentagonal-bipyramid geometry [MnN3O4 .] with different secondary structure units. Ll ligand adopts the mu 2 -1 kappa N-3,N',N '':2 kappa O-2,O' mode to coordinate with mononuclear manganese to build a single chainlike compound 1, while L2 employs mu(3) -1 kappa N-3,N',N '':2 kappa O-2,O':3 kappa O-1 and 1 kappa O-1 modes to link dimeric Mn2O2 to exhibit a double chainlike 2. Both compounds display weak antiferromagnetic coupling interactions.