本研究分析了3个栽培密度水平（D1，30.0 cm×20.0 cm；D2，30.0 cm×16.7 cm；D3，30.0 cm×13.3 cm）对辽粳212稻瘟病和纹枯病发生程度及产量的影响。结果表明，随着生育期进程的推进，辽粳212稻瘟病和纹枯病呈逐渐加重的趋势；随着栽培密度的增加，发病率和病情指数也逐渐增加。与D3处理相比，D1处理纹枯病发病率降低26.15个百分点、病情指数降低5.91个百分点，叶瘟发病率降低43.71个百分点、病情指数降低21.51个百分点，穗瘟发病率降低42.47个百分点、病情指数降低16.41个百分点。不同栽培密度下产量由高到低顺序是D1>D2>D3。栽培密度与辽粳212的叶瘟和纹枯病的发病率、病情指数呈极显著正相关关系，与穗瘟发病率呈显著正相关关系，产量与密度呈极显著负相关关系。可以通过适当降低栽培密度来控制辽粳212的稻瘟病和纹枯病的发生程度，并提高辽粳212的产量。

The effects of three planting densities（D1: 30.0 cm×20.0 cm, D2: 30.0 cm×16.7 cm, D3: 30.0 cm×13.3 cm） on the occurrence of rice blast and sheath blight and yield components of Liaogeng 212 were analyzed. The results showed that the rice blast and sheath blight disease of Liaogeng 212 were gradually aggravated with the growth of rice. Compared with D3 treatment, the incidence of sheath blight of D1 treatment was decreased by 26.15 percent point and the disease index was decreased by 5.91 percent point, the incidence of leaf blast was decreased by 43.71 percent point and the disease index was decreased by 21.51 percent point, the incidence of panicle blast was decreased by 42.47 percent point, the disease index was decreased by 16.41 percent point. The order of yield under different plant densities were D1>D2>D3. The incidence of leaf blast and sheath blight had extremely significant correlation with planting density, the incidence of panicle blast had significant positive correlation with planting density, the yield and planting density showed a significant negative correlation. It is possible to control the occurrence of rice blast and sheath blight of Liaogeng 212 by reducing planting density, and the yield of Liaogeng 212 could be improved.