Abstract: According to different planted shrubs under Osmanthus fragrans 'Xionghuang', the study area was divided into 5 plot types (A: planting Camellia japonica; B: planting Acer palmatum 'Atropurpureum'; C: planting Loropetalum chinense var. Rubrum; D: planting Euonymus japonicus 'Aurea-marginatus'; E: control). The effects of different shrubs on the growth and photosynthesis of O. fragrans 'Xionghuang' were studied with the morphological and structural indexes of shrubs (height, density and coverage) as variables, and the morphological and structural indexes of the understory shrubs most suitable for the growth of O. fragrans 'Xionghuang' were determined, which provided scientific basis for solving the problem of slow growth. The results showed that: (1) The understory shrubs promoted the growth of O. fragrans 'Xionghuang', among which B had the most promotion effect, followed by C, and the effect of B on the branch growth of O. fragrans 'Xionghuang' at the first, second, third and fourth time was significantly higher than that of A, D and E (P<0.01). (2) The manifestations of P_n, G_s and Tr were B>C>D>A>E, P_n and G_s of B and C were significantly different from those of A, D and E (P<0.01). (3) AQY, P_nmax, LCP and LSP of B were all the largest, while R_d was the smallest, followed by C, and there were significant differences between B, C with E treatment (P<0.01). (4) Branch growth was positively correlated with P_n, G_s, T_r, AQY, P_nmax, LCP and LSP, and negatively correlated with C_i and R_d. (5) Shrub density had a significant effect on branch growth, and shrub density and height had a significant effect on photosynthesis. In conclusion, height and low-density shrubs had the best promotion effect on trees. In the process of planting shrubs, reasonable understory management should be adopted, such as weed removal, fertilization and other measures to promote the height growth of shrubs, and selective cutting and other management measures to control the density of shrubs, so as to give full play to the promotion effect of shrubs on growth of trees.