Abstract: The study of two types of cooling roofs (high reflectivity roofs and green roofs) has important implications for the mitigation of high temperature in the summer in Beijing. This paper has implemented the Weather Research and Forecasting Model (WRF3.8) coupled with the Single-Layer City Canopy Model (SLUCM) to evaluate the simulation performance of the control case (case1) by this coupled model using meteorological data collected at 158 stations in Beijing. Seven cases with roofs of different albedos (cases2-4) and green roofs with different cover ratios (cases5-8) are conducted for sensitivity studies. The results of the study show that:(1) in the urban area of Beijing, the roof whose albedo is 0.85 (case4) has a better cooling effect than the 100% (case8) green roof, the average temperature in case4 drops by 0.90℃ and the cooling in case 8 is 0.46℃; (2) with the albedo increase of 0.1 in the roof, the maximum temperature in Beijing will decrease by 0.27℃. And the increase in the proportion of green roofs will also result in a decrease in temperature. With every 10% increase in the green roof, the maximum temperature will decrease by 0.16℃; (3) the two types of cooling roofs have significant impacts on the urban heat island (UHI). Compared with case1, the maximum UHI in case4 drops by 1.47℃ during the daytime from 13:00 BT to 14:00 BT, which is higher than the cooling effect shown in case8; (4) the cooling effect of the cooling roofs can reach 1.2 km height above the city, and the turbulence is also significantly reduced. During 12:00-18:00 BT of the three days, compared with case1, the height of the planetary boundary layer in case4 and case8 on average are reduced by 669 and 430 m, respectively.