A pair of new dioxomolybdenum(VI) complexes, [MoO2L1(MeOH)] center dot [MoO2L1(MeOH)] (1) and [MoO2L1(MeOH)] center dot [MoO2L1(MeOH)] (2), where L1 and L2 are the dianionic forms of N'-(2-hydroxy-3-methoxybenzylidene)-2-hydroxy-3-methylbenzohydrazide and N'-(3-ethoxy-2-hydroxybenzylidene)-2-hydroxy-3methylbenzohydrazide, respectively, have been synthesized and characterized by elemental analysis, FT-IR spectra, and single crystal X-ray determination. The crystal of (1) is triclinic: space group P-1, a = 8.106(2), b = 13.412(3), c = 18.045(3) angstrom, a = 83.634(2), beta = 84.809(2), gamma = 87.746(2), V = 1941.0(7) angstrom(3), Z = 2, R-1 = 0.0382, wR(2) = 0.0919. The crystal of (2) is triclinic: space group P-1, a = 7.350(2), b = 11.292(3), c = 24.914(3) angstrom, a = 85.213(2), beta = 82.411(2),gamma = 71.012(2), V = 1936.1(7) angstrom(3), Z = 2, R-1 = 0.0425, wR(2) = 0.0877. The Mo atoms in the complexes are coordinated by one phenolate O, one imine N and one enolic O atoms of the benzohydrazone ligand, two oxo O atoms, and one solvate O atom, forming octahedral coordination. In the crystal structures, adjacent two complex molecules are linked by methanol and ethanol ligands through intermolecular O-H .... O hydrogen bonds, forming dimers. The catalytic property of sulfoxidation for the complexes was studied.