In the development process of the fruit of Lycium barbarum L.,we measured the starch content and starch metabolism related enzyme activities in the fruit,and observed plasmid ultrastructure and starch histochemical localization in the peel cells systematically.The results showed that:(1)Starch content in the fruit of L.barbarum L.increased first and then reduced with the development of fruit,14 d after flowering its content reached the highest(13.85 mg·g^-1).(2)In the fruit,α amylase activity and β amylase activity along with the fruit mature,presents the tendency of increase gradually,and α amylase activity is always higher than β amylase activity.(3)Histochemistry and ultrastructure studies have shown that the amyloplast enriched much more starch grain before veraison stage(24 days after blossom),but starch grain almost disappeared during the second rapid growth stage,meanwhile the starch grain was not observed in chloroplast.The starch was a transient form of carbohydrate accumulation during fruit development,which was available to form sugar concentration gradient between “source” and “sink” and accelerate sugar unloading from phloem and played an important role in maintain the sink capacity in early phase fruit.With the sink capacity increasing during the second rapid growth stage,the starch was degraded into reducing sugars by the action of amylase and accumulated in fruit parenchyma cell.