Abstract: Based on 2-year-old Cinnamomum camphora and Lindera megaphylla seedlings,the photosynthetic indices of Cinnamomum camphora and Lindera megaphylla under different water treatments,were measured and then their photosynthetic physiology response mechanisms were analyzed.The results indicated that chlorophyll content and photosynthesis rate aimed to both of Lindera megaphylla and Cinnamomum camphora increased at first,and then decreased under water logging and drought stress conditions.With the prolong of water stress′s time,transpiration rate dropped gradually,yet the conductivity was increasing gradually,and obviously increased in the later period of stress.Compared to Cinnamomum camphora,Lindera megaphylla was more sensitive to water stress,and tolerance was enhanced,showing more flooding and drought tolerance.