Abstract: The coupling relationship between carbon and water cycles in terrestrial ecosystems is one of the hot spots of global change research. However, the current research is mainly in arid and semi-arid areas, and the coupling mechanism of terrestrial carbon and water in humid regions is still unclear. Based on Remote Sensing and GIS, the coupling relationship between vegetation net primary productivity (NPP), soil moisture and evapotranspiration in Taihu Lake Basin was analyzed at different spatial and temporal scales. The results showed that the coupling relationships between NPP and hydrological elements were significantly different at different spatial and temporal scales: Based on all monthly data during the study period, evapotranspiration and NPP were significantly positively correlated, while soil moisture in 99.86% regions was negatively correlated with NPP. In the interannual scale, the correlation between the three was weakened. At the seasonal scale, soil moisture and NPP were negatively correlated in 82% of regions in spring, summer and autumn, among which spring was the most significant, which was mainly related to the difference of land cover and plant growth period. The study further found that the correlation between the three was closely related to topographic factors, which was manifested as a trend of weakening with the increase of slope or altitude. Finally, it was found that the Random forest model (RF_All model) based on the whole period monthly scale hydro-meteorological elements could estimate and predict the NPP of the basin well (R2 = 0.97，RMSE = 4.16 gC m-2 a-1，Bias = 0.37 gC m-2 a-1). The conclusion of this study has important theoretical significance for formulating the policy of ecological construction and sustainable development of Taihu basin under the background of global change.