Abstract: The difference between land surface and air temperature (simply as Ts-Ta) plays an important role in the heat exchange of the atmospheric boundary layer. Therefore, it’s necessary to study the Ts-Ta. By utilizing the observation data of temperature in Chengdu in 2014, this article analyzed the characteristics of the variation of the Ts-Ta, and the simulation ability of the numerical model WRF(Weather Research and Forecasting Model)on the Ts-Ta in the typical basin city, Chengdu, is discussed. The results showed that the Ts-Ta in Chengdu was 2.20℃, mostly distributed between 0-2℃. The maximum Ts-Ta was in spring, followed by summer, winter, and autumn. The diurnal variations of Ts-Ta in different seasons were similar; however, the amplitude was different. The numerical model WRF was used to simulate the Ts-Ta between the typical sunny days in Chengdu. The simulation results of three common land surface process parameterization schemes were compared and analyzed. The variation trend of the three parameterized schemes was consistent with the observation, and the Noah scheme can better simulate the variation characteristics of the temperature difference in Chengdu. By combination of schemes, the simulation ability of ground temperature difference was improved.