The relation between soybean nutrient area per plant and yield, its yield components, development of plant and root under square planting on Hefeng 43 and Suinong 10 with close growing period but different pod habit was discussed.The nutrient area per plant with the maximum yield on both of Hefeng 43 and Suinong 10 was 442.60 cm2［(21.03 cm×21.03 cm),22.59 plant/m2］and effective nutrient area per plant were 850cm2［(29.15 cm×29.15 cm), 11.76 plant/m2］ and 733.85cm2［(27.82 cm×27.82 cm), 13.63 plant/m2］.Leaf area index, dry weight per plant, length of roots, surface area of roots, and volume of roots went up with increasing of nutrient area per plant. The linear correlation coefficients between nutrient area per plant and pod number per plant, grain number per plant, grain weight per plant were significant.