Abstract: Previous studies have shown that Lake Taihu's microclimate condition and local thermal environment play an important role in sustainable development of the surrounding cities and atmospheric macro-control. In order to more precisely simulate the lake-air interaction in Lake Taihu, the CLM4-LISSS shallow lake land-surface process parameterization scheme is coupled with the Noah land-surface process model in WRF in the present study. The performance of CLM4-LISSS shallow lake process scheme on the simulation of near-surface meteorological conditions in the region of Lake Taihu is evaluated using observations from the lake platforms and the observational stations in the land. Furthermore, on the basis of the coupled model simulation, the effect of Lake Taihu on the thermal environment in the surrounding cities is analyzed in the present study. The results are as follows. The lake surface temperature simulated by CLM4-LISSS lake surface process scheme can realistically reflect the variational trend of observed temperature. Differences are found in the simulated 2 m air temperature by the two land surface schemes. The Root Mean Square Error (RMSE) of 2 m air temperature between CLM4-LISSSS simulation and observations is 1.77℃, which is better than that between Noah simulation and observations (2.22℃). The correlation coefficients between observations and simulations by the two schemes are 0.88 (CLM4-LISSS) and 0.84 (Noah), respectively. The RMSEs of 10 m wind speed and correlation coefficients between observations and simulations by the two schemes are 1.93 m/s and 0.72 (CLM4-LISSS) and 2.78 m/s and 0.68 (Noah), respectively. Lake Taihu has a significant impact on the thermal environment of the surrounding cities. Near-surface temperature can be decreased by 0.5-0.7℃ averagely at 15:00 BT in August due to the lake effects and the influence range of the lake is up to 60 km. Near-surface temperature can be increased by 0.7-1℃ averagely at 06:00 BT in August and the influence range of the lake is up to 50 km. The cold air brought by the lake breeze suppresses the vertical motion induced by the urban heat island effect. Under the control of hot weather, average planetary boundary layer (PBL) heights over the urban areas of Suzhou, Wuxi and Changzhou can be decreased by 300, 400 and 100 m, respectively during the daytime. The maximum temperature decrease within the PBL in the region of Wuxi can reach up to 0.5-0.7℃. The result indicates that the lake breeze can disrupt the heat island circulation structure in the region of Wuxi, change the distribution of near-surface heat and water vapor fluxes, restrain the vertical expansion of urban heat island and affect the entire region of Wuxi. The change in local thermal circulation may have a great impact on local climate and the transport and dispersion of pollutants. Accurate parameterization scheme of lake surface process is significant for weather forecast and air quality simulation and climate study.