以生长在人工气候室内的青钱柳〔Cyclocarya paliurus （Batal.） Iljinsk.〕1年生平茬实生苗为试验材料，研究了不同施氮量〔每盆施氮量分别为0（CK，对照）、3（N1）和6（N2） g〕对青钱柳幼苗生长、全碳和全氮含量、碳氮比、总酚含量和积累量及叶中多酚合成途径关键酶活性的影响。结果表明：施氮量对青钱柳幼苗的株高，地径，不同器官的干质量、全氮含量、碳氮比及总酚含量和积累量，根和茎中全碳含量以及叶中苯丙氨酸解氨酶（PAL）、肉桂酸-4-羟化酶（C4H）和4-香豆酸辅酶A连接酶（4CL）活性均有显著（P<0.05）影响。株高、地径和单株总干质量均在N1处理下最大，分别较对照增加41.9%、14.8%和43.3%。根、茎和叶中全碳和全氮含量在N2处理下最高，在对照下最低；碳氮比则在对照下最高，在N2处理下最低。根、茎和叶中总酚含量在对照下最高，分别为31.04、20.63和24.45 mg·g^-1，在N1处理下最低。单株根、茎和叶的总酚积累量以及总积累量也在对照下最高，分别为211.49、69.26、66.10和346.85 mg，在N2处理下最低。叶中PAL、C4H和4CL活性的变化趋势与总酚含量一致，也在对照下最高，在N1处理下最低。Pearson相关性分析结果显示：根、茎和叶的碳氮比与单株对应器官的总酚积累量呈显著或极显著正相关。本研究结果可为青钱柳叶用林培育的氮肥合理施用提供参考。

 Taking one-year-old coppicing seedling of Cyclocarya paliurus （Batal.） Iljinsk. growing in phytotron as experimental material， the effect of different applying amounts of nitrogen 〔applying amount of nitrogen per pot of 0 （CK， the control）， 3 （N1）， and 6 （N2） g， respectively〕 on growth， contents of total carbon and total nitrogen， ratio of carbon to nitrogen， content and accumulation of total phenolics， and key enzyme activity in polyphenol synthesis pathway of leaf of C. paliurus seedling was studied. The results show that applying amount of nitrogen has significant （P<0.05） effects on height， ground diameter， dry mass， total nitrogen content， ratio of carbon to nitrogen， and content and accumulation of total phenolics in different organs， total carbon content in root and stem， and activities of phenylalanine ammonia lyase （PAL）， cinnamate-4-hydroxylase （C4H）， and 4coumarate CoA ligase （4CL） in leaf of C. paliurus seedling. Height， ground diameter， and total dry mass per plant are the largest under N1 treatment， with an increase by 41.9%， 14.8%， and 43.3% compared with the control， respectively. The contents of total carbon and total nitrogen in root， stem， and leaf are the highest under N2 treatment and the lowest under the control， and ratio of carbon to nitrogen is the largest under the control and the smallest under N2 treatment. Total phenolic content in root， stem， and leaf is the highest under the control， with a value of 31.04， 20.63， and 24.45 mg·g^-1， respectively， and the lowest under N1 treatment. Total phenolic accumulation in root， stem and leaf and their total accumulation per plant are also the highest under the control， with a value of 211.49， 69.26， 66.10， and 346.85 mg， respectively， and the lowest under N2 treatment. The change trend of activities of PAL， C4H， and 4CL in leaf is consistent with total phenolic content， which is also the highest under the control and the lowest under N1 treatment. The result of Pearson correlation analysis shows that ratio of carbon to nitrogen of root， stem， and leaf is significantly or obviously significantly correlated with total phenolic accumulation in corresponding organ per plant. The result of this study can provide a reference for rational application of nitrogen fertilizer in leaf forest cultivation of C. paliurus.