has been traditionally used as a functional food in China. A hydroponic experiment was conducted to determine the effects of N and P additions on photosynthesis and chlorophyll fluorescence (ChlF) of seedlings. N and P additions significantly altered photosynthesis and ChlF in the seedlings, but responses of these parameters to the N and P concentrations varied at different developmental stages. The greatest net photosynthetic rate ( ) and actual photochemical efficiency of PSII (Ф) occurred in the treatment of 150.0 mg(N) L and 25.0 mg(P) L addition, whereas the highest maximum quantum yield of PSII (F/F) and water-use efficiency (WUE) were recorded with 150.0 mg(N) L and 15.0 mg(P) L on the 60 day after treatment. Significantly positive correlations of with leaf relative chlorophyll content, transpiration rate, WUE, F/F, and Φ, as well as the Ф with the F/F, were found Our results indicated that an optimal addition of N and P nutrients depends on their coupling effects on the photosynthetic capacity and PSII photochemistry.