Abstract: 【Objective】To elucidate the effects of soil erosion and soil and water conservation measures on the terrestrial carbon cycle, and to clarify their carbon-enhancement effects, functioning pathways, and assessment and accounting methods. 【Methods】The processes of organic carbon detachment, transport, mineralization, depositional burial, and stabilization were reviewed. A meta-analysis based on 1015 observations from 196 publications was conducted to compare the effects of tillage, forest–grass, and engineering measures on soil organic carbon across different regions and implementation periods, and an assessment and accounting framework was developed. 【Results】Soil erosion can act as both a carbon source and a carbon sink, and its net effect is governed by erosion intensity, depositional environment, and temporal scale. Forest–grass measures produced the greatest overall carbon-enhancement effect, with stronger responses in red-soil regions but a relatively slow onset. Engineering measures achieved stable medium- and long-term carbon gains through sediment interception and deposition, whereas tillage measures generally increased soil organic carbon within 5–10 years. By enhancing vegetation carbon assimilation, increasing soil carbon inputs, and reducing erosion intensity and carbon oxidation rates, these measures generated synergistic effects through vertical carbon sink enhancement, lateral soil conservation and carbon retention, and erosion reduction and emission mitigation. 【Conclusion】The carbon-enhancement effects of soil and water conservation measures vary markedly among regions and implementation periods. Comprehensive assessment should encompass all three effects, whereas project-level accounting should focus on measurable increases in vegetation and soil carbon stocks, with clearly defined baseline scenarios, monitoring procedures, and parameter selection to avoid double counting and support regional comparisons and standardized assessments.