Abstract: Taking grafted seed orchard of E. dunnii as research material, the study compared the chloroplast pigment, photosynthetic physiology, soluble protein, soluble sugar and free amino acid of flowering and non- flowering plants. The results showed that: the chloroplast pigment, stomatal conductance, transpiration rate, apparent quantum efficiency of non-flowering plants were more obviously higher than that of flowering plants, but the blossom leaf net photosynthetic rate, water use efficiency, intercellular CO2 concentration of flowering plants were lower than that of non-flowering plants. Comparing with non-flowering plants, flowering plants had lower assimilation ability and stronger dissimilation ability, and photosynthetic coefficient was smaller in flowering plants; the soluble protein, soluble sugar and free amino acid content of flowering plants were higher than that of non-flowering plants. By comparing the photosynthetic physiology, physiological and biochemical characteristics of flowering and non-flowering plants, the paper could provide a theoretical basis for the research of grafted seed orchard.