Abstract: In order to investigate the effects of different nitrogen fertilizer rates on the growth of Pinus armandii seedling, 300 seedlings with the same growth rate were selected and divided into 5 groups for different nitrogen fertilizer rates. The results showed that the root length, seedling height and base diameter of Pinus armandii seedlings increased first and then decreased with the increase of nitrogen fertilizer application. Root biomass, stem biomass, leaf biomass, total biomass and root-shoot ratio all increased first and then decreased. Nitrogen fertilizer application rate of 15 g/plant was the most favorable for the growth of Pinus armandii seedling.