With the aim to solve the drawback on the traditional fructose production from inulin hydrolysis in acidic aqueous solution, the high pressure CO2—water system for the inulin hydrolysis was studied instead of the traditional acidic aqueous solution. The effects of CO2 pressure, reaction temperature and reaction time on fructose production from inulin hydrolysis were investigated. The results showed that the hydrolysis degree of inulin was positively related with CO2 pressure and reaction time, and increased at first followed by decreasing with reaction temperature rise. Under an optimum reaction condition of CO2 pressure 20MPa, reaction temperature 70℃ and reaction time 3h, the hydrolysis degree of inulin reached 94.9%, which implies that the inulin is efficiently hydrolyzed to produce fructose in the high pressure CO2—water system, and the complicated operations and pollution of the traditional acid hydrolysis process were avoided. 