Abstract: Evapotranspiration（ET）is an important variable in the hydrological cycle and is becoming an alternative variable to replace the observed streamflow for parameter calibration in the hydrological models. In this study,the streamflow simulations produced by the SWAT（Soil and Water Assessment Tool）model based on two different calibration strategies,which use observed streamflow and ET as the calibration variable respectively,are compared to investigate the impact of parameter calibration based on ET on the streamflow simulation in the upper and middle part of the Xiang River Basin. Besides,the differences brought by the basin are analyzed. Multisource ET is used in the study,including the ET products from Moderate Resolution Imaging Spectroradiometer（MODIS）（named MOD16A2）,Global Land Amsterdam Model（GLEAM）and Global Land Assimilation Data System（GLDAS）. The results show that the SWAT model based on the parameter calibration using GLEAM,GLDAS and MOD16 can generate satisfactory streamflow simulation performances. For the calibration based on the three ET products,the NSE values of simulated streamflow are close to that calibrated based on the observed streamflow in the calibration period. In particular,the NSE values of the simulated streamflow are more than 0.50 at the Shuangpai Station and more than 0.70 at the Hengyang Station. Additionally,in the validation period,the NSE values of simulated streamflow obtained at the Shuangpai Station are more than0.58,which are comparable to that calibrated based on the observed streamflow（0.60）. At Hengyang Station,the streamflow simulation performance generated from the parameter calibration based on ET is slightly better than that based on observed streamflow. It is worth mentioning that the SWAT model calibrated based on GLDAS and MOD16 can generate streamflow simulation with NSE of 0.72,which are significantly more than that calibrated based on the observed streamflow（NSE=0.6）. This study shows that remote sensing ET product has great potential for parameter calibration of hydrological models,and is more suitable for basins with larger areas. The strategy in this study can provide an insight into hydrological modeling in those ungauged regions.