Abstract: Soil carbon sequestration can improve the soil quality, ensure the food security and mitigate the climate change. The integrated rice-Azolla imbricata cropping is a traditional rice cultivation method in China, which can increase the rice yield. However, the short-term effects of integrated rice-Azolla imbricata cropping on the carbon sequestration in paddy soil remain unclear. In order to explore the effect of integrated rice- Azolla imbricata cropping model on soil carbon sequestration in paddy fields in southern China, a field experiment was carried out in northern Fujian, and three different field management measures were set up, which were no fertilization treatment (CK), conventional chemical fertilization treatment (F) and the conventional chemical fertilization combined with integrated rice- Azolla imbricata cropping (FA). Then, the net primary productivity (NPP), total carbon sequestration, CO₂ and CH₄ emissions from soil heterotrophic respiration were measured, and the net ecosystem carbon budget (NECB) and the sequestration rate of soil organic carbon (SOC) were calculated. The results showed that the integrated rice- Azolla imbricata cropping could significantly increase the net primary productivity of rice, the total carbon sequestration of rice and the total amount of CO₂ emitted by soil heterotrophic respiration (P＜0.05), but there was no significant difference in CH₄ emission between FA and F in the paddies. The net ecosystem carbon budget of different treatments ranged from 2 751.04 to 4 900.61 kg·hm⁻², indicating that all treatments were net carbon sinks. Moreover, FA significantly increased the net ecosystem carbon budget and soil organic carbon sequestration rate (P＜0.05). These results have shown that the conventional chemical fertilization combined with the integrated rice- Azolla imbricata cropping was an effective management method to improve the SOC sequestration in paddy fields in southeastern China and had great potential in mitigating the climate change.