为确定杂交籼稻Y两优886的适宜施氮量和理想群体冠层结构，测定了不同氮素水平下Y两优886的产量、叶面积指数、叶绿素含量、光合辐射利用等指标。结果表明，随着氮肥用量的增加，叶面积指数和叶绿素SPAD值呈逐渐增加趋势，而水稻灌浆-成熟期的PAR截获率、干物质净积累量、PAR转化率、PAR利用率呈先上升后降低的趋势；N390处理的产量最高，叶面积指数、叶绿素SPAD值、PAR利用及转化都达到较高水平。390 kg/hm2是Y两优886合理的施氮量，有利于该品种的高产高效栽培。

In order to make clear the appropriate amount of nitrogen and ideal population canopy structure of indica hybrid rice Y liangyou 886, the yield, leaf area index （LAI）, SPAD value, photosynthetic radiation utilization and some other parameters were investigated and analyzed under six nitrogen levels. The results indicated that LAI and SPAD value showed a gradually increasing trend, PAR interception efficiency, net dry matter accumulation, PAR conversion efficiency and PAR utilization efficiency at filling stage showed a trend of increasing at first and then decreasing, with the increase of nitrogen fertilizer. Under 390 kg/hm2 of nitrogen, the grain yield of Y Liangyou 886 was the highest, and LAI, SPAD value, PAR conversion and utilization efficiency also reached a high level. 390 kg/hm2 is the appropriate nitrogen fertilizer amount for Y Liangyou 886, which is beneficial to the high yield and high efficiency cultivation.