In order to improve understanding of whole course of fruit growth, we tested the content of total sugar and total acid which could provide scientific evidence to improve the genetic quality and species cultivating so that relevant producing and managing measures could be taken. The results show that the total sugar in fruit juice of Bingtang orange and Bingtang navel orange is gradually increased, together with the gradual increase of the content of total sugar .From September 5 to October 15, the content of total sugar is slowly increased,and ...