Taking the rice flour with the same particle size of fresh and aged rice as research materials， the changes of particle size distribution， microstructure， water binding capacity and rice gel texture after ultrasonic treatment were compared， in order that the effects of ultrasonic treatment on the dissociation between starch granules and rice gel texture of fresh and aged rice were investigated， revealing the underlying reasons of quality deterioration caused by rice aging. The results showed that the starch granules were difficult to dissociate after rice aging， the peak volume fraction of starch granules with intermediate particle size decreased from 64.907% to 40.927%， and the water binding capacity decreased significantly from 1.46 g/g to 1.35 g/g. Ultrasonic treatment could significantly promote the dissociation between starch granules in aged rice， significantly increase the water binding ability， and then improve the gel texture of aged rice. After ultrasonic treatment for 30 min， the water binding capacity of aged rice could be improved to 1.44 g/g， approaching to the level of fresh rice， and the gel texture of aged rice was close to that of fresh rice. After ultrasonic treatment for 180 min， for the aged rice， its particle size distribution， water binding capacity， stickiness， elasticity and chewability of rice gel were better than or reached the level of fresh rice. Rice aging caused the difficulty of dissociation between starch granules and reduces the water binding capacity， which could be one of the underlying reasons for the quality deterioration of rice aging. Ultrasonic treatment could significantly improve the gel texture of aged rice， which was of great significance to reveal the aging mechanism of rice storage and regulate rice quality.