On the basis of an original lake model with a one-dimensional eddy diffusion scheme, a new lake model for the heat and mass exchange processes between the atmosphere and water bodies has been developed. Temperature is used as the predicted variable, which improves the new numerical calculation method, and a lake sediment module is added for shallow lakes. The new lake model is verified and compared with other four lake models by using observation data of Lake Kossenblatter in Germany recorded in May-October 2003. We further use this model to simulate the energy exchange process that occurred over Erhai Lake in Yunnan Province, China, in January-December 2012. A comparison of the model results and observed data indicates that the new lake model can effe ctively simulate the diurnal and seasonal variations of water temperature in Erhai Lake. The agreement between computed and measured temperature profiles is very good, with an error of less than 2℃. Compared with the water temperature simulation, the heat flux simulation results are poor. The model significantly underestimated the sensible heat flux with a maximum difference of 33% of the measured value. This result is likely caused by errors in observation, the data packing and correction method, and simplistic surface parameterization.