[Objective] This study aimed to investigate the characteristics of high-yield soybean varieties.[Method] The agronomic traits of six high-yield soybean varieties and other 57 summer sowing ones were investigated from 2007 to 2010.[Result] The higher-yield summer sowing soybean varieties should have higher plants （R=0.551 6＊）,more effective pods （R=0.739 7＊）,more seeds per pod （R=0.318 9）,more flowers per plant （＞130）,higher pod setting rate （＞52％）,smaller ratio of aborted pods （＜40％）,longer tap roots （more than 20 cm） and lateral roots （more than 15 cm）,shorter bottom nodes （the length of six bottom nodes should be less than 25 cm）,lower center of gravity of the plant （＜40 cm）,greater stem dry weight,higher dry matter transformation rate and continuously increasing seed weight in late seed filling stage.The ideal growth stage model for summer sowing soybean was that the durations between adjacent stages of sowing,seedling emergence,flowering,seed setting and maturity stage were 5,29-33,29-33,32-36 d,respectively.[Conclusion] This pattern could not only satisfy the ecological conditions for double cropping system,but also balance the full development of vegetative and reproductive growth,promote the yield formation of summer sowing soybean.
