The implementing of large-scale ecological restoration projects?(ERPs) has made Southwest China Karst a hotspot of global greening.?However, there is still a lack of systematic studies to reveal the impacts of vegetation restoration on different hydrological processes in this area.?Therefore, we obtained meteorological?and hydrological?parameters, remote sensing?vegetation index, and GRACE (Gravity Recovery and Climate Experiment) data from eight typical karst catchments covered by ecological restoration projects in Southwest China Karst?from 2002 to 2021, and analyzed the long-term trends of hydrological processes and water resource. Meanwhile, the?impacts?of climate change and vegetation greening?on hydrological processes and water resources in?these?catchments were evaluated using the water balance equation, partial correlation, and the generalized linear mixed effect model (GLMM).?The results showed?that: (1) the Normalized Difference Vegetation Index (NDVI), forest area, precipitation, runoff, evapotranspiration, soil moisture, runoff coefficient, and terrestrial water storage in the catchments?covered by ERPs?in Southwest?China Karst?showed?increasing trends?from 2002 to 2021, indicating that the ERPs implementation over the past 20 years have increased the NDVI and available water resources. However, the solar radiation showed a?decreasing trend during the same period. (2) The results of the GLMM?showed?that the contributions of NDVI to runoff, evapotranspiration, and soil moisture variations in the catchments covered by ERPs were 2%, 23%, and 11%, respectively. The contributions?of precipitation?to runoff, evapotranspiration, and soil moisture?changes?were?43%, 2%, and 23%, respectively. The contributions?of air temperature to runoff, evapotranspiration, and soil moisture?changes?were?3%, 13%, and 3%, respectively. The contributions?of solar radiation to runoff, evapotranspiration, and soil moisture were?16%, 34%, and 29%, respectively. These results?indicate?that the?major?hydrological processes?in?Southwest China Karst?are mainly controlled by climatic factors rather than the vegetation greening induced by ERPs; (3) among different karst landscapes, the hydrological responses?of karst peak forest plains and karst peaked depressions?to vegetation restoration?were more remarkable than karst trough valleys. Hence, ERPs should consider the diverse hydrological responses of different karst landscapes to vegetation restoration in the future. In summary, our?findings?indicate that the vegetation greening induced?by ERPs?in Southwest China Karst?during 2002-2021 has enhanced??evapotranspiration, yet?the increase in precipitation due to a humid climate?in the same period offsets such?water loss. Therefore, the available?water resource in Southwest China Karst has not decreased during the past 20 years. These findings will help to evaluate?the eco-hydrological effects of future ecological restoration projects in karst regions.