The Chimonanthus praecox of six years old was used as material to study the effects of pruning on photosynthesis and leaf anatomical structure. The photosynthetic parameters were measured and anatomic characteristics was observed in vigorous growth period of the leaf. The results showed that the pruning significantly increased the average of diurnal variation of net photosynthetic rate (Pn), stomata conductance (Gs) , transpiration rate (Tr) of Chimonanthus praecox leaf , the apparent mesophyll conductance (ALMC), the chlorophyll a , total chlorophyll content , the ratio of chlorophyll a to chlorophyll b , width of stoma , the length of stoma, width of stomata aperture, stomata density , the thickness of leaf , palisade tissue , the thickness rate of palisade and sponge tissue , however, significantly decreased the intercellular CO2 concentrations(Ci). Correlation analysis showed that the net photosynthetic rate was significantly positively correlated with Tr, Gs, ALMC, PAR, Ta, the ratio of chlorophyll a to chlorophyll b, the specific leaf weight, the width of stoma, the length of stoma and width of stomata aperture. In conclusion, the pruning could change the leaf morphological characteristics and anatomical structure characteristics and photosynthetic efficiency of the leaves, which were beneficial to the growth of Chimonanthus praecox.