The first indirect radiative forcing and climatic effect of sulfate are investigated by using a Regional Integrated Environment Modeling System (RIEMS). The RIEMS can generally represent cloud and radiation processes by comparison with the MODIS data and the results from other models. The first indirect radiative forcing of sulfate over East Asia is negative and varies seasonally, with seasonal means being -0.88 W/m2 in winter, -2.27 W/m2 in spring, -2.41 W/m2 in summer, -1.47 W/m2 in autumn, and annual mean being -1.75 W/m2. The spatial distributions of simulated cloud droplet effective radius are similar to the MODIS data, showing larger effective radius over the sea (6－15 μm) than that over land (4－10 μm), and the decreasing trend from Southeast China to Northwest China, but the model results are systemically smaller than the MODIS data. The indirect radiative effect of sulfate generally leads to a decrease in the ground temperature, with maximum surface cooling reaching 1.5℃ in Chongqing and its vicinity in spring and autumn. The vapor decreases in winter and spring due to the ground temperature decreasing, but its changes seem much more complex in summer and fall, not only decreasing but also increasing, because the vapor transport is more complex. The changes in precipitation are consistent with those in water vapor, and show a general decrease trend over eastern China. The precipitation decreases in spring and winter over most areas of eastern China (0－60 mm), but the situation is complex in summer and autumn. In summer, the precipitation increases in the Sichuan Basin, the middle and lower reaches of the Yangtze River, and large areas south of the Yangtze River (0－150 mm), whereas in most areas of Northeast China and the North China Plain, the precipitation decreases (0－90 mm). The spatial averages of these changes over specific regions of China show that the ground temperature decreases in all regions and all seasons except Northeast China in summer where the ground temperature increases (0.2℃), the maximum decrease in the ground temperature appears in the region of Central China (as large as 0.5℃) in autumn. The changes in precipitation in these regions are smallest in winter (-0.1－0 cm), largest in summer. In summer, the decrease in regional mean accumulated precipitation can reach 1.7 cm in Northeast China, whereas the precipitation increases by about 0.2 cm in the region of Central China.