Temporal variation in the soil CO2 emission from the worlds largest mangrove forest was studied on a monthly basis. In situ measurements were carried out from three different parts of the mangrove forest, i.e. (1) deep forest (with limited tidal influence), (2) rooted (with pneumatophores, medium tree density and tidally active), and (3) un-rooted region (tidal flat). Subsequently, the role of soil salinity, temperature and the enzyme activities (Urease, β-D glucosidase and Dehydrogenase activity) in regulating the microbial mineralization processes were also studied to understand their contribution to the soil CO2 emission. Irrespective of the sampling locations, the highest and lowest CO2 efflux was recorded during month from October to January and from June to September, respectively. Among the three different regions, the highest and the lowest CO2 emission was recorded from the deep forest (8.34 ± 1.04 mmol C m-2h-1) and un-rooted soil (0.81 ± 0.07 mmol C m-2 h-1), respectively. Soil CO2 emission did not show any significant response to salinity. However, soil temperature and available enzyme activities showed significant control over soil CO2 emission. The results indicated that the microbial community in this tidally active zone is well adapted within a large salinity range. Among the soil enzymes, β-D glucosidase activity showed the highest contribution, in regulating the soil CO2 emissions, in all the studied locations. © International Society for Tropical Ecology.