Abstract: [Objective]To study the effects of girdling on alternate bearing of olive trees and on altering of photosynthesis in a long-term (125 days after girdling), and to investigate the changes of fruit characteristics (the rate of flower buds to lateral buds, fruit setting and fruit yield) and photosynthesis,carbohydrate and nitrogen contents in leaves.[Method]Using 16-year-old ‘Leccino’ olive trees as experimental materials, the effects of branch girdling on fruit characteristics and leaf photosynthesis of olive trees were studied. [Result]Branch girdling in semi-dormancy increased significantly the rate of flower buds to lateral buds and fruit setting (30 days after flowering) of ‘On’ and ‘Off’ olive trees, but the final fruit setting (before fruit harvest) and final fruits yield did not increase. 30 days after girdling, the concentration of soluble sugar and the rate of carbohydrate to nitrogen increased significantly, the concentration of starch increased obviously, the concentration of nitrogen, net photosynthetic rate (Pn) and stomatal conductance (Gs) decreased significantly, the intercellular CO2 concentration (Ci) changed little in ‘On’ and ‘Off’ olive trees. However, when the effect of accumulation of soluble sugar and starch in leaves after girdling had disappeared, Pn and Gs decreased significantly also, while Ci increased significantly. Also, the rate of carbohydrate to nitrogen in leaves on girdling brunches was significant higher than that on control branches, the leaf water use efficiency (WUE) was significant lower than that on control ones, which may be the reason why girdling could promote the flowering but could not promote the fruit bearing and fruits yield. [Conclusion]Branch girdling in semi-dormancy may promote flowering, but may not increase final fruit yields. In a short time, the decrease of Pn after girdling attributed to end-product feedback inhibition.