The Co-Mo2C was prepared by in-situ reduction of ammonium molybdate and cobalt nitrate with isosorbitol-tar at high temperature and characterized by X-ray diffraction (XRD), N2 adsorption (BET), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The prepared Co-Mo2C was used to catalyze the oxidation of dimethyl succinate (DMSS) by O2 to form dimethyl 2,5-dihydroxyterephthalate (DHTA). The effects of calcination temperature, atomic ratio of Co to Mo and oxidation conditions were investigated. The results show that: Co-5Mo2C with a specific surface area of 134 m2/g can be prepared by in situ reduction of ammonium molybdate and cobalt nitrate at 850 ℃ for 4h with isosorbitol-tar. Co-5Mo2C-4, Co:Mo=1:5 (mol. r.), exhibits good performance due to the synergistic effect of Co and Mo2C. Using Co-5Mo2C-4 as a catalyst, under 1.1 MPa O2 at 110 ℃ for 4h, 88.22% yield of DHTA with 99.98% purity can be obtained. The yield of DHTA is decreased by 1.7% and 7.3% after the catalyst reused for 6 times and 9 times, respectively.