In this study, four types of rice starch with different amylose contents ( Younuo 3: 0%; Daohuacan: 10.90%; Juliangyou: 21.03%; Huayouxiangzhan: 28.46%) were used to investigate the effect of acid hydrolysis time on the structure and properties of rice starches. After undergoing acid hydrolysis for different time, the changes in the hydrolysis ratio, particle morphology, crystallization properties, and solubility of hydrolyzed rice starches were measured and used as indicators to evaluate the effects of hydrolysis time. The results showed that rice starches with different amylose content shad different acid-resistant abilities, and thus hydrolysis time had different effects on the structure and properties of the rice starches with different amylose contents. The extent of acid hydrolysis in rice starch was negatively related to the amylose content, as evidenced by the fact that approximately 50% Younuo3 was hydrolyzed, whereas only 30% of Huayouxiangzhan was hydrolyzed. All starch granules showed a degree of breakage after acid hydrolysis, and the cross observed in starch under polarized light deformed before it completely disappeared. With the same acid hydrolysis time, the rice starches with higher amylose contents showed lower breakage rates. Acid hydrolysis did not affect the A-type crystal pattern of the starch in the studied samples; however, with increasing hydrolysis time the relative crystallinity and the solubility of the rice starches increased.