Abstract: The effects of spraying 3 plant growth regulators with different concentrations on the N, P and K contents and stoichiometric characteristics of each organ of the 1-year-old Fraxinus malacophylla seedlings were analyzed by orthogonal test. The results show that content of N, P, K and ratio of N, P, K chemical measurement in different organs and different treatment have significant difference. The treatment of A₂B₁C₂ is the best solution to spray F. malacophyllai seedlings, the ZT mass concentration of 50 mg/L, the IAA mass concentration of 50 mg/L, the GA₃ mass concentration of 150 mg/L. In addition, the leaf has the most N and K in different organs. Stem has the most P in different organs. Different plant growth regulator under the appropriate concentration can significantly promote accumulation of N in the leaf and P in the stem. Restriction element of F. malacophylla seedlings is N and K. We can increase fertilizer of N and K to promote seedling growth.