The soybean yield formation and seed quality in response to the elevated atmospheric O3 (eO3) were analyzed in open top chamber (OTC) simulation systems using 3 soybean cultivars as Suinong 4,Suinong 8 and Dongsheng 1. The results showed that soybean yield decreased by 33% across 3 soybean cultivars when the concentrations of atmospheric O3 increased 40 nL·L~(-1). The yield response to eO3 varied in the 3 soybean cultivars. The minimum decrease of 23% was found in Suinong 4, while the maximum of 41% was found in Suinong 8. Compared with the control,the yield components of soybean were also changed under eO3. The stepwise regression analysis showed that the seed size(x1) and seed number per plant (x2) could be used for estimating soybean yield change under eO3 by a model of y =-3. 639+ 0. 098x1-0. 285x2 (P < 0. 05) . In addition, eO3 had pronounced influence on soybean seed quality,which caused significant increase in soybean seed protein concentration (2. 8% to 4. 6%,P < 0. 05) but significantly decrease in seed oil concentration (-4. 2% to-7. 8%,P < 0. 05) in the three tested cultivars.