Ozone is believed to be an important environmental pollutant causing severe losses of crops production under global change scenarios. Technical countermeasures to easing ozone stress would help ensure food security, among which adding silicon might be one of the practical approaches. Open-top chambers (OTCs) were applied in determining the effects of ozone (normal air, <40 μg/kg O₃ or elevated O₃, (80±5) μg/kg, 7 h/d) and silicon (Si-free, 0 mg/kg or +Si, 100 μg/g) on plant height, leaf area, chlorophyll content, antioxidant system and yield of soybean after anthesis. Our results indicated that, under normal air condition, compared with Si-free treatments, +Si significantly increased the amount of biomass of soybean roots, total biomass and grain weight per plant(14%,5% and 20%)(P<0.05). While under the elevated O₃ environment, against Si-free treatments, silicon application could maintain a high leaf area of soybean. Use of silicon also significantly increased chlorophyll content and SOD, POD, CAT activity, while decreased MDA content. The biomass of soybean roots, shoot, root-shoot ratio and yield of per plant were further improved by 29%,18%,19%,9% and 17%, respectively (P<0.05). Our findings might provide theoretical support for the reasonable soybean cultivation and management in alleviating the damage of ozone pollution.