Indonesia's peatlands store more carbon than the nation's forests combined, positioning them as critical components in global climate change mitigation. Nevertheless, anthropogenic activities such as drainage, land conversion, and intensive agriculture have significantly impaired their ability to store carbon. This study quantifies soil carbon stocks and evaluates key biophysical factors across three types of peatland use (natural, restored, and degraded or oil palm used peatland) in Geragai District, East Tanjung Jabung Regency, Jambi Province, Indonesia. Thirty-nine observation points were selected to represent each type of land use. Measurements included bulk density, water content, organic carbon content, soil pH, peat depth, and peat thickness. Laboratory analyses of soil organic carbon (OC) content use the Loss-on-Ignition (LOI) method. Soil carbon stocks in the upper 50 cm of the peat layer were calculated using bulk density, soil organic carbon content, and sampling depth, following Agus et al. (2012) and IPCC (2019). The results indicated that natural peat swamp forests possessed the highest carbon stocks (30.9 ± 8.7 t C ha⁻¹), followed by the restored land (23.1 ± 14.2 t C ha⁻¹) and the lowest in the degraded oil palm land (24.4 ± 12.7 t C ha⁻¹). These differences are attributed to hydrological conditions, the degree of peat decomposition, and alterations in soil properties resulting from drainage. Elevated pH and bulk density corresponded with reduced organic carbon and carbon stocks, whereas higher water content was associated with higher carbon stocks. Maintaining shallow groundwater levels (less than 40 cm) and restoring hydrology through canal blocking and native species planting were identified as effective strategies for safeguarding soil carbon stocks. The protection and restoration of peatlands in Jambi Province are therefore integral to climate change mitigation policies.