A General Circulation Model, BCC_AGCM2.0 from National Climate Center of China, was used in this work. And the effective radiative forcing (ERF), newly defined by IPCC AR5, was adopted in discussing the radiative forcing and climate response for methane. The ERF due to the change in methane concentration from pre-industrial was 0.49 W/m~2. Because of the change in methane concentration, the global annual mean surface temperature increased by 0.31℃, and precipitation increased by 0.02 mm per day. And there were remarkable increases (by approximately 4%) in the cloud cover in high latitudes of both Northern and Southern Hemisphere, and the cloud cover decreased (by approximately -3%) sharply in tropical areas.