Water is a green solvent for chemical reaction, but it is not suitable for the dehydration of carbohydrates to HMF, as the water can accelerate many side products such as levulinic acid (LA), formic acid (FA) and humins. In contrast to water, ionic liquids with unique physicochemical properties are proved to be good reaction medium for the conversion of carbohydrates into be good reaction medium for the conversion of carbohydrates into HMF. However, the large-scale synthesis of HMF is limited by the high cost of ionic liquids. Encouragingly, dimethylsulfoxide (DMSO) shows high ability to dissolve carbohydrates, stabilize HMF and reduce side-reaction. Thus, good results of the dehydration of carbohydrates can also be attained in DMSO