７ 个杂交组合三年的试验结果表明，两系杂交稻在北方粳稻区有一定的杂种优势。９ 个主要经济性状平均值均大于大值亲本和对照品种。其中单株分蘖、穗粒数、千粒重、谷草比有较强的超亲优势和竞争优势。相关分析证实，穗粒数、结实率与产量呈正相关，达显著、极显著水平。 Three-year experiment results of seven hybrid combinations showed that two-line hybrid rice had some heterosis in northern japonica rice. The average of nine major economic traits was greater than that of the large parent and control breeds. Among them, tillers per plant, grains per spike, 1000-grain weight, aspartat ratio had strong superiority and competitive advantage. Correlation analysis confirmed that grain number per spike, grain yield and yield were positively correlated, reaching significant, very significant level.