Abstract:In order to investigate the effects of saline-alkali on the organic carbon mineralization process, a method integrating field sampling and lab simulating experiment is used. In the study, exploring the saline-alkaline soil in Qianguo Irrigation District in Western Jilin Province, 4 paddy fields with different saline alkali degrees (P1, P2, P3, P4) were chosen as the experimental subjects. The experiment recorded the soil CO2 emission flux on the 1st, 4th, 7th, 10th, 14th, 21st, 28th, 35th and 70th day of the incubation period. Combining the physical and chemical properties of soil to compare the dynamic changes of CO2 flux in the progress of paddy field cultivation simulation among the subjects. The results showed that P1, P2 and P3 were weakly alkaline soils and P4 was strongly alkaline soil. The SOC content of each plot was significantly different and there was a surface enrichment, which was significantly negatively correlated with the degree of alkalization (r=-0.945). The accumulation process of SOC mineralization and culture time was consistent with the First order kinetic model Ct=C0(1-e-kt).In the initial stage of mineralization, the amount of CO2 released was large, and the release intensity decreased rapidly. The mineralization rate decreased slowly with time and decreased to the minimum at the end of the culture period. The study interprets that the SOC mineralization process is affected by a variety of factors. In saline alkaline soils, ESP is the main influencing factors of this process. Salinization of soil inhibits the rate of soil C cycle, which has a greater impact on the C sink than the C source process. The intensity of SOC mineralization reaction, the accumulation of mineralization reaction and the completeness of mineralization reaction increase with the increase of SOC content, and decrease with the increase of ESP level.