It has been predicted that elevated atmospheric CO₂ will increase enzyme activity as a result of CO₂-induced carbon entering the soil. The objective of this study was to investigate the effects of elevated atmospheric CO2 on soil enzyme activities under a rice/wheat rotation. This experiment was conducted in Wuxi, Jiangsu, China under China FACE (Free Air Carbon dioxide Enrichment) Project system. Two atmospheric CO2 concentrations ((580±60) and (380±40) μmol•mol^-1)) and three N application treatments (low nitrogen,LN 150 kg•hm^-2, normal nitrogen, NN 250 kg•hm-2 and high nitrogen, HN 350kg•hm^-2) were included. Soil samples (0～10 cm) were collected for analysis of β-glucosidase, invertase, urease, acid phosphates and β-glucosaminidase activities. Results revealed that with elevated atmospheric CO₂ β-glucosidase activity significantly decreased (p<0.05) at low N application rates; had no significant effect with a normal N application rate; and significantly increased (p<0.05) with a high N application rate. For urease activity, at low and normal N application rates (but not high N application rate), elevated atmospheric CO₂ significa ntly increased (p<0.05) it. With acid phosphatase elevated atmospheric CO₂ only had significant higher effects (p<0.05) at high N application rates. Under different CO₂ concentration, effects of N fertilization are also different. Soil β-glucosidase activity at ambient CO₂ concentration decreased with N fertilization, while it increased at elevated CO₂ concentration. In addition, invertase and acid phosphatase activities at elevated CO₂ concentrations, significantly increased (p<0.05) with N treatments, but there was no effect with the ambient CO₂ concentration. For urease activity, at ambient CO₂ concentrations, N fertilization increased it significantly (p<0.05), whereas at elevated CO2 concentrations were not significant. Additionally, with β-glucosaminidase activity, there were no significant effects from N application. In general, then, elevated atmospheric CO₂ increased soil enzyme activity, which may be attributed to the following two factors: (1) elevated atmospheric CO₂ leading to more plant biomass in the soil, which in turn stimulated soil microbial biomass and activity; and (2) elevated atmospheric CO₂ that increased plant photosynthesis, thereby increasing plant-derived soil enzymes.