On the base of the structural development of pericarp of Lycium barbarum L.,the ultrastructure of phloem and the flesh sink-cells during fruit development was studied by the electron microscope technology.The results showed:(1)with the fruit growing,the sieve plate with large and much sieve pores,where active substance transport was observed in SE.Most,if not all,of the CC were transfer cells.Numerous plasmodesmata were observed between SE and CC (SE/CC),but there were almost no plasmodesmata between the SE/CC complexes and phloem parenchyma cell.Plasma membrane invagination was observed in adjacent between companion cell and phloem parenchyma cells.There was a symplasmically isolated between the SE/CC complex and its surrounding cells over the fruit development,which was available to sugar phloem unloading by apoplast pathway.(2)Numerous plasmodesmata were also observed between the phloem parenchyma cells,on the contrary,there were almost no plasmodesmata between phloem parenchyma cell and fruit parenchyma cell and even between fruit parenchyma cells.(3)The larger intercellular space among the fruit parenchyma cells and apoplast space caused by cell wall and plasma membrane invagination,which were in favour of sugar post-phloem transporting by apoplastic pathway.Vesicles were observed to participate in assimilates unloading and transporting.Based on the above results,we concluded that it was an apoplast way that existed in phloem unloading and after unloading of photosynthate transportation in fruit of Lycium barbarum L..