Abstract: The hydrolysis of 5-chloromethyl furfural(CMF) in pure water or water/acetone system to 5-hydroxymethyl furfural(HMF) was studied. The effects of hydrolysis reaction conditions(such as solvent system, alkali neutralizer, temperature and CMF addition amount) on the hydrolysis of CMF were investigated, and the kinetics of the hydrolysis reaction was analyzed. The results showed that the water/acetone system is helpful to reduce the side reaction of HMF, and the addition of sodium disulfite(Na₂S₂O₄) could further prevent the generation of humus. The optimal hydrolysis conditions are as follows: 1 g CMF was added with 0.35 g CaCO₃ in a mixture of 10 mL water/acetone with volume ratio of 1∶4, and incubated at 353.15 K for 28 min. Under these conditions, the CMF conversion rate was 97%, the yield of HMF was 85%, and the yield of by-product levulinic acid(LA) was 6%. The separation rate of HMF increased from 50% to 86% with the addition of Na₂S₂O₄. The kinetic study results showed that the activation energy of CMF hydrolysis was 12.3 kJ/mol and the hydrolysis rate constant k₁=5.56exp(-1.23×10⁴/RT) in water/acetone system.