Abstract: The main composition of rice is starch. Rice quality is decided by the properties and compositions of starch. It is the key enzymes of starch synthesis play an important role in the process of starch synthesis in rice. This report summarized the functions and regulation mechanism of ADP-glucose pyrophosphorylase (AGPase), Starch synthase (SS), Starch branching enzyme(SBE) and Starch debranching enzyme(DBE). We also discussed several problems in current studies.