CuBr2-pyridine ionic liquids with different alkyl side chain and anion were used as the catalyst for one-step liquid-phase synthesis ofdimethoxymethane(DMM) by oxidation of methanol.And it was found that CuBr2-N-ethylpyridinium bromide exhibited the best catalytic activity.The Effects of composition and concentration of catalyst, reaction temperature, oxygen pressure andreaction timeon the reaction were investigated.The results show that the conversion of methanol could be 19.6% and the selectivity of DMM could reach 92.3% under the optimum conditions: n(N-ethylpyridiniumbromide):n(CuBr2) of 1:1,the catalyst concentration of 0.04g/mL, the reaction temperature of 130℃, the oxygen pressure of 3.0MPa and the reaction time of 4 hours. After being reused 9 times, the activity of CuBr2-N-ethylpyridinium bromide was still kept.