Abstract: A set of field experiments have been made in the island riparian zone of Yueyang in the Dongting Lake downstream of the Three Gorges Dam, for the real-time monitoring water level and temperature of the river, as well as the groundwater level, soil moisture content and temperature distribution of the island profile. Based on the analysis of the heat flux and the hyporheic exchange rate in the island riparian zone to describe the characteristics of the water and heat transfer quantitatively and portray the response relationship between the groundwater level, water temperature and air temperature. The results show that: there is a strong positive correlation between internal heat flux and air temperature, daily average temperature can be used to calculate the heat flux. The change range of hyporheic exchange rate obtained by the soil moisture content at different depths of monitoring well T1 is -5.34×10^-6-6.78×10^-5m/s. In winter, the change of groundwater level will delay the time when the heat flux changes from negative to positive. The island loses heat during the complementation process between the river and the groundwater of the island riparian zone, the lower the groundwater level, the more frequent the fluctuations and the greater the heat loss, the heat loss mainly concentrated at 0.5-0.7 m below the ground. The results reveal the impacts of dam operation on the downstream island riparian zone hyporheic zone, which will provide the reference for the further ecological impact assessment of the hyporheic zone.