通过杂交稻汕优 5 5 9不同密度试验 ,探讨了地膜旱管稻密度对产量及其构成因素的影响 ;分析了密度与分蘖成穗率、粒叶比、干物质生产量等群体质量指标的关系。研究结果表明 ,密度与产量呈抛物线型的曲线变化关系 ,过大或过小都会因成穗数、穗粒数的变化而影响产量。汕优 5 5 9适宜密度为 18.0～ 19.5万穴 /hm2 ,其分蘖成穗率高、粒叶比大、中后期干物质生产能力强 ,易获得较高产量 The effects of density of dry film mulched rice on yield and its components were discussed through different density experiments at Shanyou 559. The effects of density and tillering rate, grain-leaf ratio and dry matter yield relationship. The results show that there is a parabolic curve between the density and the yield. If the density is too large or too small, the yield will be affected by the change of the number of spikes and grains per spike. Shanyou 5 5 9 suitable density of 18.0 ~ 195,000 points / hm2, the tillering rate of the ear, grain-leaf ratio, dry matter production capacity in the late, easy access to higher yields