This paper reports the research results of effects of low concentration SO2 on soybeans bearing. The experimental plants at different vegetation periods were exposured in the open-top chamber. The results indicated that the long-term fumigation had a greater effect on soybeans bearing. It significantly decreased number of pod/per plant and number ofseed/per plant,but did not decrease number of seed/per pod. This indicates that less number of pod/per plant results in less number of seed/per plant. The fumiga...