通过设置秧田每公顷１５０ｋｇ（Ａ）、２２５ｋｇ（Ｂ）、３００ｋｇ（Ｃ）３个播种量，对两系粳杂７０优双九作双晚种植的分蘖成穗特点进行定株观察，结果表明，以净秧田播量１５０ｋｇ／ｈｍ２，培育多蘖壮秧，每穴１粒种苗的栽植方式；以及提高栽插质量并加强肥水管理，适度控制中后期群体，是提高成穗率和产量、降低用种成本的有效途径。 By setting three sowing rates of 150kg (A), 225kg (B) and 300kg (C) per hectare in seedling field, we observed the tillering characteristics of two-line japonica hybrid rice 70 Youshuanshuangji as double tillers. The results showed that, To sow seedling net yield of 150kg / hm2, cultivate more tiller seedling, per hole seedlings planted way; and to improve the planting quality and to strengthen fertilizer and water management, moderate control group, is to increase the ear rate and yield, reduce An effective way to use cost.