To investigate the effects of elevated CO2 concentration on sugar metabolism and fat metabolism of soybean. The high-oil soybean variety“Jinda-70”was used as material, and two treatments were set up in a controlled chamber: CK (CO2 concentration 400 μmol/mol) and EC (CO2 concentration 600 μmol/mol). The whole growth period of soybean was in the controlled gas chamber. The portable gas exchange system Li-6400 was used to measure the indexes of the photosynthetic parameters, chlorophyll content, glucose metabolism and fat metabolism at the bulking stage, and the yield indexes at the harvest stage were also measured. The results showed that the contents of chlorophyll a, chlorophyll b and total chlorophyll were significantly increased by increasing CO2 concentration, and the net photosynthetic rate and water usage efficiency of soybean also significantly increased by 59.7% and 63.2%. The activities of sucrose phosphate synthase and isocitrate lyase in leaves significantly increased by 28.8% and 215.0% under high CO2 concentration, while the activities of succinate dehydrogenase, acetyl-CoA carboxylase, and diacylglycerol acyltransferase significantly decreased. With the increase of CO2 concentration, soluble sugar content, sucrose content, sucrose synthase and isocitrate lyase activities were significantly decreased, while the activities of isocitrate dehydrogenase, succinic dehydrogenase and acetyl-CoA carboxylase were significantly increased by 248.2%, 75.0% and 15.8%. In addition, the seed weight per plant, pod number per plant, and 100-seed weight of soybean significantly increased by 25.6%、23.4% and 21.1% under increased CO2 concentration. In soybean leaf, sucrose metabolism and pentose phosphate pathway were strengthened, whereas tricarboxylic acid cycle and fat metabolism were weakened at seed filling stage in soybean. In soybean seed, pentose phosphate pathway, tricarboxylic acid cycle and fat metabolism were strengthened along with weakened sucrose metabolism. The results will help to understand the effects of elevated CO2 concentration on sugar metabolism and lipid metabolism in soybean, and provide theoretical basis for the production and management in soybean under climate change scenarios in the future.