During global climate change,the concentration of CO_2 in the atmosphere has increased from 270 mumol ? L~(-1) prior to the Industrial Revolution to 390 mumol ? L~(-1) in 2013. It is expected that CO_2 will increase to 700 mumol?L~(-1) by the end of the century. The increase of atmospheric CO_2 concentration is likely to affect soybean production. The impacts of elevated CO_2 on photosynthetic rate,leaf area, chlorophyll content, phytohormones, nitrogen fixation, biomass accumulation and yield are reviewed. Many studies stated that photosynthetic rate of soybean had positive response to elevated CO_2,while a decrease trend was observed in other studies. This is likely due to photosynthetic acclimation in response to elevated CO_2. Elevated CO_2 generally facilitates the accumulation of the chlorophyll content, but there was no response in some summer-sowing cultivars of soybean. The magnitude of leaf area,nitrogen fixation,biomass and yield in response to elevated CO_2 varied depending on the extent of CO_2 rise,cultivars,growth stages and other experimental conditions. The information on the effect of elevated CO_2 on phytohormones is very rare to our knowledge. It is worth further investigating on the mechanisms of yield in response to elevated CO_2,including enzyme activities in relevant photosynthetic physiology, and metabolisms of carbon and nitrogen etc. Such work is fundamental to the high-yield breeding and the improvement of environmental adaptability in soybean in the future.