本文研究了20个品种大豆比叶重(SLW)的变异性。新品种的SLW,一般地高于老品种。盛花期和鼓粒期上层叶的SLW高于其它生育期的SLW。盛花期和鼓粒期的平均SLW分别为50.64和161.53g/m~2。花末期的SLW下降为47.51g/m~2。一日中的SLW一般从8时至16时逐渐增加,以傍晚时为最高。大豆盛花期和鼓粒期上层叶的SLW能够充分表现出大豆基因型的特征。 In this paper, the variability of specific leaf weight (SLW) of 20 cultivars was studied. The new varieties of SLW, generally higher than the old varieties. The SLW of the upper leaves at full flowering and boll stage was higher than that at other growth stages. The average SLW of flowering stage and drum stage were 50.64 and 161.53 g / m ~ 2, respectively. The final SLW decreased to 47.51 g / m ~ 2. The daytime SLW generally increases gradually from 8:00 to 16:00 and is highest in the evening. The SLW of the upper leaves at full-flowering and bolting stage showed the characteristics of soybean genotype.