Retrogradation properties of normal and waxy rice starch gels prepared by conventional heating,microwave heating and ultrasonic-microwave synergistic heating were investigated in this study.Our results showed that non-waxy rice starch was more susceptible to heat treatments.During the same period,the retrogradation rate,the changes of gel strength,and the hydrolysis degree of normal rice starch gelatinized by microwave and ultrasonic-microwave synergistic heating were significantly slower than that by conventional heat.The results also found that the microstructure of non-waxy rice starch gels obtained from microwave and ultrasonic-microwave synergistic heat treatments was denser.The retardation mechanism of microwave heating and ultrasonic-microwave synergistic heating on starch retrogradation is probably due to the less broken granules and lower leached amylose.