The effects of hot-air drying, microwave drying and vacuum freeze-drying on the quality of instant rice, such as the time of rehydration, rehydrayion rate, Iodine-blue value, enzymolysis rate and absorbency of rice water, were researched. The quality of instant rice produced by vacuum freeze-drying was shown to be the best among the three methods used, with which the rehydrate time and the rehydration rate were only 5.0min and up to 3.50, respectively. Additional, when vacuum freeze-drying was accepted as drying method, the other indexes are also better that those using other methods.