Abstract: The ATPase activities of the stem storage tiessue were assayed in ten sugarcane varieties by biochemical methods. The ATPase activities of stem storage tissue were significantly and very signfi-cantly positive correlation with brix and sucrose content, and very significantly negative correlation with the storage cell size. With the age the ATPase activities of all varieties would become higher, and this was in accordance with the accumulation of sugar, the decrease of the cell size and the changes of environment temperature. The results showed that the ATPase activity was not only correlative with the transport of sugar, but also affected the accumulation of sucrose and sucrose content. It was suggested that the reasons why the varieties with small cell had high quality and why the decrease of cell size was associated with sugar content and ripenning period were based on their increase of uptake area and ATPase activity to some extent.