Abstract: A sugar-increasing IBA agent, ROC16, was sprayed on the sugarcane leaves during seedling, shooting, and sugar accumulating period to study its effect on sucrose content and yield of the plants.The results showed that spraying IBA 5times produced better effect than spraying 4times.With 5sprayings, the sucrose contents of the sugarcanes treated with 1 000 x, 600xand 500 xIBA solutions were all higher than CK at P<0.05 or P<0.01 significant level.The 600 xwas the best, which resulted in sugarcanes with a sucrose content higher than CK every month.The yields of the treated sugarcanes were all higher than that of CK.The differences were significant, with the 600 xbeing the best.It appeared that 600 xIBA solution for the spraying gave the most desirable effects on sucrose content, gravity purity, and yield, as compared to CK or other treatments.