【目的】森林是三峡库区重要的生态屏障,研究该地区森林生态系统化学计量特征可深入了解生态系统的养分循环、限制作用以及稳定机制。【方法】通过对三峡库区库首森林生态系统的7个站点进行典型取样,研究了包括乔木、灌木和草本30种植物的107个样品叶片中碳(C)、氮(N)和磷(P)的化学计量学特征。【结果】三峡库区库首森林生态系统植物叶片中有机碳(OC)、全氮(TN)和全磷(TP)的含量变化范围分别为352.0~506.3、8.3~48.6和0.5~2.5 mg/g,平均值为450.2、18.6和1.2 mg/g;叶片C/N、C/P和N/P的变化范围为7.6~56.5、158.8~799.3和7.3~40.2,平均值为28.6、450.4和16.9。不同生活型植物叶片的养分组成存在显著差异,乔木叶片的有机碳含量要明显高于灌木和草本,而草本植物的叶片全氮和全磷的含量要明显高于乔木和灌木;落叶乔木叶片的全氮、全磷含量及N/P的值要明显高于常绿乔木,但有机碳含量及C/N和C/P的值则相反。不同生活型植物有机碳与全氮(磷)含量的相互关系也存在差异,草本植物叶片有机碳与全氮(磷)含量存在极显著负相关,乔木叶片有机碳与全氮含量呈显著的负相关,但与全磷含量不相关,灌木叶片有机碳与全氮(磷)含量不相关;不同生活型植物叶片全氮和全磷含量均存在极显著正相关。【结论】三峡库区库首森林生态系统植物叶片有机碳含量处于中等水平,而全氮和全磷含量相对较低,磷缺乏是限制该区植被生产力的关键元素。 【Objective】 The forest is an important ecological barrier in the Three Gorges Reservoir Area. Studying the stoichiometric characteristics of forest ecosystems in this area can deeply understand the nutrient cycle, the limiting effect and the stability mechanism of the ecosystem. 【Method】 Seven typical sampling sites of the forest ecosystem in the Three Gorges Reservoir Area were used to study the carbon (C), nitrogen (N) and phosphorus (P) contents in 107 samples from 30 species of trees, shrubs and herbs. P) stoichiometric characteristics. 【Result】 The results showed that the contents of organic carbon (OC), total nitrogen (TN) and total phosphorus (TP) in the plant ecosystem of the forest ecosystem in the Three Gorges Reservoir Area varied from 352.0 to 506.3, 8.3 to 48.6 and 0.5 to 2.5 mg / g, with the average values ​​of 450.2, 18.6 and 1.2 mg / g. The C / N, C / P and N / P ratios ranged from 7.6 to 56.5, 158.8 to 799.3 and 7.3 to 40.2, with an average of 28.6, 450.4 and 16.9 . There were significant differences in the nutrient compositions of leaves of different life forms. The contents of organic carbon in tree leaves were significantly higher than those in shrubs and herbs. The contents of total nitrogen and total phosphorus in leaves of herbaceous plants were significantly higher than that of trees and shrubs. Total nitrogen, total phosphorus and N / P values ​​were significantly higher than evergreen trees, but organic carbon content and C / N and C / P values ​​were opposite. There were also differences in the correlations between total organic carbon (TOC) and total nitrogen (P) in different living plants. There was a significant negative correlation between organic carbon and total nitrogen (P) in the leaves of herbaceous plants, and negatively correlated with organic carbon and total nitrogen But not with the total phosphorus content. There was no correlation between organic carbon and total nitrogen (P) in shrub leaves. There was a significant positive correlation between total nitrogen and total phosphorus in different living plants. 【Conclusion】 The organic carbon content of plant leaves in the forest ecosystem of the Three Gorges Reservoir Area is at a medium level, while the content of total nitrogen and total phosphorus is relatively low. Phosphorus deficiency is the key element that limits the vegetation productivity in this area.