Ecosystem conditions and processes can become ecosystem services only when they are effective for beneficiaries. In recent years, many researches have emphasized the importance of the linkage between ecosystems and their beneficiaries. However, most of them focus on the supply of ecosystem services while neglecting the beneficiaries. Taking Dongting Lake Watershed as the study area, we used universal soil loss equation (USLE) and hydrological path analysis to propose an assessment method of soil conservation service based on beneficiaries. The results show that:(1) from the perspective of ecosystem, the important area of soil conservation service in Dongting Lake Watershed covered an area of 2.8×10⁴ km², mainly distributed in the Yuanjiang River Watershed (38.14%) and Xiangjiang River Watershed (39.73%), with high soil conservation capacity. From the perspective of beneficiaries, the important area covered 1.57×10⁴ km², mainly concentrated in the Xiangjiang River Watershed (92.95%), with large beneficiaries. (2) After considering the beneficiaries, the area totaling 1.71×10⁴ km² of important level (very high) was degraded due to the small number of beneficiaries (12362 people), which was mainly distributed in the Wuling Mountain and Xuefeng Mountain in Yuanjiang River Watershed. While the area totaling 4.80×10³ km² was newly upgraded to the important level due to the large number of beneficiaries (53628 people), which was concentrated in Nanling Mountain and Luoxiao mountains in the Xiangjiang River Watershed. (3) Integrating ecosystem and beneficiary perspectives, the important area of soil conservation service in Dongting Lake Watershed covered an area of 3.28×10⁴ km², mainly distributed in the Wuling Mountain and Xuefeng Mountain in the west, the Nanling mountains and Yangming Mountain in the south, the Luoxiao mountains and Mulianjiu mountains in the east. The study analyzed the actual effectiveness of soil conservation from the perspective of beneficiaries, which was an effective supplement to the ecosystem service research. The results could provide data for soil conservation and ecological protection in watersheds and a reference for improving the support effort of soil conservation to human well-being.