In order to study the effect of different CO₂ air conditioning treatments on the quality of fresh lotus seeds postharvest storage， this study used 'Shilihe No.1' fresh lotus seeds as the test material， and under the conditions of 4 ℃ and 5% O₂， different CO₂ were used (4%， 8% and 12%). The fresh lotus was stored for 20 days under controlled atmosphere， and its appearance and nutritional quality during storage were measured. The results showed that 4% CO₂ treatment could reduce the weight loss rate and browning degree of lotus seeds， but the nutrient consumption was more serious. After 20 days of storage， the starch content (98.01 mg/g) was 6.98 mg/g lower than the control group (104.99 mg/g)； at the end of storage， browning degree， weight loss rate， reducing sugar of 8% CO₂ treatment were 1.63， 8.54%， 0.76%， respectively， POD and PPO activities were 163.44 U/(min·g)， 99.63 U/(min·g)， which were significantly lower than the control group and other modified atmosphere treatment groups(P<0.05)， while the starch content was 119.68 mg/g， which was significantly higher than that of the control and other atmospheres. 12% CO₂ treatment may cause the lotus seeds to be damaged by too high concentration of CO₂. After 20 days of storage， the a* value (-10.03) was higher than the control group (-12.68)， and the b* value (24.95) was lower than the control group (28.03)， and the browning phenomenon was more obvious than that of the control group. This researches showed that 5% O₂ + 8% CO₂ was the most suitable treatment for fresh lotus seeds storage. This treatment also showed a positive effect in reducing the nutrient consumption of lotus seeds and protecting the green of the epidermis， providing new ideas and references for the research and development of fresh lotus postharvest preservation technology.