Two manganese complexes, [Mn3(2-cba)6(phen)2] 1 (2-cba = 2-cyanobenzoic acid, phen = 1,10-phenanthroline) and [Mn2(4-fbao)2(phen)4](PF6)2.2H2O 2 (4-fbao = 4-formylbenzoic acid oxime), have been synthesized by the reaction of 2-formylbenzoic acid oxime (2-fbao, H2LI) or 4-formylbenzoic acid oxime (4-fbao, H2L2) with phen and manganese acetate in ethanol or methanol solution. A translation from the oximino (-CHN=OH) of H2L1 to cyano (-C≡N) was found in the formation of complex 1 at room temperature. The complexes were structurally determined by single-crystal X-ray diffraction. The crystal of compound 1 belongs to monoclinic, space group C21c, with a = 17.983(6), b = 23.364(7), c =14.589(5) A, β = 92.401(5)°, V = 6124(3) A3, Z = 4, C72H40Mn3N10O12, Mr= 1401.96, Dc = 1.521 g/cm3, F(000) = 2852.0, Rint = 0.0372, T = 293(2) K, μ =0.686 mm-1, the final R = 0.0644 and wR = 0.1813 for 5803 observed reflections with Ⅰ> 2σ(Ⅰ). The crystal of compound 2 is of monoclinic system, space group P21/n, with a = 13.050(4), b = 20.577(5), c = 13.323(4) A,β = 113.578(3)°, V = 3227.2(14) A3, Z = 2, C64H48F12Mn2N10O8P2, Mr = 1484.94, Dc= 1.528 g/cm3, F(000) = 1508.0, Rint= 0.0295, T= 293(2) K,μ = 0.539 mm-1, the final R = 0.0629 and wR = 0.1789 for 5298 observed reflections with Ⅰ> 2σ(Ⅰ). Compounds 1 and 2 are linear trinuclear and dinuclear manganese complexes respectively, which are both bridged by carboxylate groups of the ligands.