[Objective] The paper aimed to provide the theoretical foundation for rational using the large-seed rice.[Method] Large-seed rice 31C122、31C125 （ nearly 50 g /1 000-weight） and normal rice varieties including Jiyujing and Fuyu 333 as materials,the accumulative process for sugar and starch in seeds was compared and analyzed.[Result] Sugar content of inferior grains was higher than superior grains in all tested materials,sugar content of large seeds was lower than conventional ones;starch content of superior grains was higher than inferior grains,starch content of conventional ones was higher than large-seed rice,amylopectin content was higher than amylose content in all tested materials,amylose content of large-seed rice was lower than conventional ones;the peak of accumulation starch for superior grains of large-seed rice was later than conventional ones,inferior grains advanced;active saving period of starch for superior grains of large-seed rice was longer than conventional ones.[Conclusion] The quality of large-seed rice was better than conventional ones.
