Abstract: Considering the requirement of fast recognition of stressor risks for water environmental risk management, using a case study of the Three Gorges Reservoir (TGR) area, a land exploitation stressor assessment was established and applied. The results indicated that:1) an evaluation for determining the pressure of land development on water quality, and warnings for adverse status and changes, has been proposed. Firstly, sensitive land use types and negative land use transitions were determined using pollutant output parameters of different land use types. The sensitive area units were selected, taking into account both the land use status and trends. Finally, the early warning indicators were ascertained to carry out stressor assessment and to rate the early warning level of each unit according to its actual characteristics. 2) For the case study areas, Chongqing municipal district control unit (CU1), Fuling-Wanzhou control unit (CU2) and Kaixian section of Pengxi River control unit (CU3) were sensitive area units of water security. The early warning indicator of CU1 and CU2 were the area proportion of sensitive land use types (42.17% and 32.86% for CU1 and CU2 respectively) and the area proportion of negative land use transitions (3.43% and 1.74% for CU1 and CU2 respectively). The early warning indicator of CU3 was the area proportion of sensitive land use types with the value of 32.31%. 3) As the maximum exceeded proportion of early warning indicators of CU1, CU2 and CU3 were 163%, 33% and 19%, the early warning levels of the indicators were at the red alert level (i.e., severe warning), orange alert level (i.e., moderate warning) and yellow alert level (i.e., mild warning), respectively. In view of watershed management, both the optimization of current land use modes and the rationalization of future land exploitation are needed to reduce the pressure of land development in CU1 and CU2. Reducing the pressure of current land use status should be focused on to mitigate the risk to water security in CU3.The study showed that the proposed method of land exploitation stressor assessment for water security early warning is feasible for supporting water environment risk management in the TGR area.