Selecting Ziziphus jujuba Mill.cv.Lingwuchangzao as materials,we determined the changes of the soluble sugar contents and the activities of sucrose metabolism-related enzymes during the development of leaf and carpopodium to study the relationship between the sugar accumulation and its metabolizing enzymes in leaf and carpopodium during the development of fruit.The result showed that:(1)The leaf and carpopodium all mainly accumulated sucrose;the contents of glucose and fructose in leaf and carpopodium kept stable and increased slightly with fruit development,but the contents of sucrose decreased at early stage and increased quickly later.The content of sucrose was higher than that of glucose and fructose all the time.(2)The acid invertase(AI) activity in leaf and carpopodium was significantly higher than that of the neutral invertase(NI) during the whole growth development period of fruit.AI activity increased at early stage and kept stable at later stage,but the change trend of the activities of sucrose synthase(SS) and sucrose phosphate synthase(SPS) was different.(3)The sucrose synthase activity in the sucrose decomposition direction(SSd) plays important regulation role in accumulating sucrose in leaf and carpopodium.To sum up,the SSd plays important regulative role in accumulating sucrose in leaf and carpopodium.