Abstract: The rape variety ‘Huayouza No.62’ was used as the experimental material, the effects of mowing on photosynthetic characteristics and non-structural carbohydrates of forage rape leaves were investigated using a single-factor randomized group method, in order to provide reference for reasonable mowing of forage rape. The results showed that moderate mowing treatments（L20,L30,L40） significantly increased Pn and Tr of rape leaves for a period of time after mowing, while excessive mowing（L10） decreased Pn and Tr. With the recovery of plant growth after mowing（late mowing treatment, 35 d）,mowing significantly increased Pn and Tr of rape leaves compared with CK. Compared with CK,moderate mowing（L20,L30,L40） promoted the accumulation of non-structural carbohydrates（starch, sucrose, total soluble sugar） in leaf organs of rape.