Abstract: To reveal the ecological adaptation mechanism of Quercus semicarpifolia in the subalpine zone of the Hengduan Mountains,the leaves and growing soil of eight plots were selected,and the C,N and P contents and their stoichiometric characteristics of leaves and growing substrate soil were measured,and the growth-limiting elements were determined.The ecological stoichiometry homeostasis model was used to determine the state of the alpine Quercus leaves.The soil C,N and P contents of the selected eight plots ranged from 38.86-70.19,3.54-9.46 and 0.61-2.05 g·kg^-1,with soil ω（C）∶ω（N） 5.65-16.07,ω（C）∶ω（P） 36.98-74.42 and ω（N）∶ω（P） 4.41-12.90,mean values were 9.48,51.79 and 6.54,respectively.Leaf C,N and P contents ranged from 428.31-473.86,21.22-31.68 and 2.21-3.68 g·kg-1,leaf ω（C）∶ω（N）,ω（C）∶ω（P）,and ω（N）∶ω（P） were 14.16-22.46,121.41-215.86 and 6.99-12.84,with mean values of 17.36,164.39 and 9.68,respectively.The alpine Quercus leaf N and P contents were higher than the global average.Leaf N and soil P,leaf N and soil ω（C）∶ω（N）,leaf ω（C）∶ω（P） and soil ω（N）∶ω（P）,leaf ω（C）∶ω（N） and soil ω（N）∶ω（P）,and leaf ω（C）∶ω（P） and leaf ω（N）∶ω（P） were highly significantly and positively correlated in each plot（P＜0.01）.In addition,the leaf stoichiometric homeostasis index of alpine Quercus were probed in terms of 1/H absolute values,while 1/H_ω（N） was-0.181-0.141,1/H_ω（P） was-1.255-1.206,and 1/H_{ω（N）∶ω（P）} was 0.391-0.960.The results indicated that each alpine Quercus 1/H_ω（N） was in the homeostasis state,1/H_ω（P） and 1/H_{ω（N）∶ω（P）} were mostly in the weakly homeostasis state,weakly sensitive and sensitive state.Leaf ω（N）∶ω（P） ratio was less than or close to 16,illustrating that alpine Quercus in this region tended to be not deficient in both N and P elements.Alpine Quercus might overstore N and P elements to adapt to the changing external habitat,but still had a more conservative strategy for the use of external P elements.The alpine Quercus forests in this region had formed a good nutrient supply and return relationship with the soil in the long-term succession process,which had formed a relatively complete and stable subalpine forest ecosystem.