Abstract: The efect of meteorological factors on agronomic characters in diferent develop periods of summer soybean is studied in this paper．The results show that by increasing the accumulated temperature in devdoping period of summer soybean，the better plant and yield characters can be obtained．The meteorological factors of seeding-flowing period have a marked effect on the plant character of summer soybean．The efficient ramification commence node and growing legumen height have relationships with the meteorological factors in this period and sowing-seeding period ．The number of growing legumen and yield per plant have a marked positive correlation with the precipitation and precipitation days in this period ，and have no correlation with the meteorological factors in prophase and anaphase of develop period ．The plant height，stem diameter，and node amount of caulis have no correlation with the meteorological factors in prophase and anaphase of develop period also ．The meteorological factors in flowing- maturing period mainly affect the 100-grain weight of summer soybean．