Based on the temperature observation data of 14 stations in the hinterland of the Three Gorges Reservoir (TGR) region during the period of 1961 to 2014, after detection and adjustment of homogeneity for annual mean temperature, the climate characteristics of temperature changes since the impoundment of TGR are analyzed.The mean temperatures before and after impoundment are compared, and also the effect of the water area change on regional climate is analyzed by choosing stations of near TGR and far from TGR. Results show that there was an increasing temperature trend in the past 54 years over the TGR region，which is consistent with the temperature change over Southwest China and the global. But in the recent 11 years， the expanding water surface area of the reservoir seems to increase the warming in winter and decrease the cooling in summer