The performance of IAP/LASG climate system model FGOALS-s2 in the simulation of present-day climate in the Southern Hemisphere is assessed. The future changes in the southern hemispheric climate are projected for four Representation Concentration Pathways (RCPs). The results show that the major features of climate mean states of the Southern Hemisphere are well simulated, including the double jet phenomenon in June-July-August (JJA), although the north (south) branch is weaker (stronger) than the reanalysis. Under the four RCPs scenarios, the surface air temperature will become warmer, except in the south Atlantic-Indian ocean basin, and the warming amplitude over land is greater than that over the sea. Meanwhile, precipitation will increase in the entire hemisphere, except in the South Indian Ocean and in the center of the South Pacific Ocean. Under all RCP scenarios, the subtropical high in the Southern Hemisphere tends to be enhanced, while the circumpolar low tends to become deeper. The precipitation changes in December-January-February (DJF) and over sea are more obvious than those in JJA and over land. Under the four RCPs scenarios, the intensity of the Mascarene High (MH) will be weakened in the beginning but will be enhanced from the 2030s, while the Australain High (AH) will intensify in the beginning of the 21th century but will become weaker from the 2030s. The future evolution of Antarctic Oscillation (AAO) is scenario dependent but clearly tends to be intensified under RCP6.0 and RCP8.5 scenarios. The changes in AAO under the different RCPs scenarios are dominated by different temperature changes in the vertical direction. For example, both RCP6.0 and RCP8.5 emission scenarios lead to an enhanced meridional temperature gradient and thus to an enhanced mid-latitude westerly jet that is in favor of a stronger AAO.