Abstract: A vertical two dimensional hydrodynamic-temperature model is established for calculating variation in water temperature in reservoirs. The parameter calibration is carried out by comparing two sets of the observation data from the natural channel and the same types of reservoirs located nearby. According to the two sets of calibrated parameters， the water temperature in Reservoir D during the verification period and the complete process of the water temperature distribution in Reservoir A have been simulated respectively. The numerically simulated results indicate that the data from natural channels and the same types of the reservoirs located nearby can be used in the model parameter calibration when the other conditions remain the same. The numerically simulated results show the same tendency but different values applying those two sets of calibrated parameters. It is confirmed that the parameters obtained from the nearby reservoirs are more reasonable and close to realities. Therefore， it is recommended that in the reservoir water temperature simulation， the data from the same types of reservoirs located nearby are preferred， and the data from the natural channels can be used as a reference for analysis and studies of variation in the reservoir water temperature when the data are insufficient.