Abstract: 【Objective】 To study the effects of spraying different concentrations of foliar fertilizer on the photosynthetic characteristics and quality of winter jujube under the condition of arched shed cultivation. 【Methods】 The winter jujube was treated with different concentrations of foliar fertilizer in different plot experiments. 【Results】 (1) the net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs) and intercellular CO₂ of winter jujube leaves increased significantly when foliar fertilizer was applied at lower concentration.The concentration (Ci) of winter jujube leaves was significantly lower than that of the control; PN of winter jujube leaves under high concentration treatment was significantly higher than that of the control, TR was significantly reduced, Gs and Ci had no significant difference with the control; LSP, LCP, Pmax and AQY of winter jujube leaves increased first and then decreased with the decrease of treatment concentration.(2) The maximum photochemical efficiency (Fv / Fm), the photochemical quenching coefficient (qP), the apparent electron transfer rate (ETR) and the non photochemical quenching coefficient (NPQ) of winter jujube increased first and then decreased with the decrease of foliar fertilizer concentration, but the non photochemical quenching coefficient (qN) changed in the opposite direction.(3) The treatment of foliar fertilizer increased the weight of single fruit, the vertical and horizontal diameter of fruit, increased the content of reducing sugar, total sugar and sucrose, while the content of vitamin C decreased.The total acid content of 0.005 g/L treatment increased compared with the control, which might be some acid substances that had not been transformed in time. 【Conclusion】 Spraying suitable concentration of foliar fertilizer enhances photosynthesis and improves fruit quality of winter jujube and the concentration of 0.005 g/L achieves the best effect for improving its photosynthesis and fruit quality.