In this study, the Slab Ocean Model (SOM) is coupled with an Atmospheric General Circulation Model (AGCM) which developed in University of Kangnung based on the land surface model of Biosphere-Atmosphere Transfer Scheme (BATS). The purposes of this study are to understand radiative role of clouds considering of the atmospheric feedback, and to compare the Clouds Radiative Forcing (CRF) come from the analyses using the clear-cloud sky method and CGCM. The new CGCM was integrated by using two sets of the clouds with radiative role (EXP-A) and without radiative role (EXP-B). Clouds in this two cases show the negative effect -26.0 Wm-2 of difference of radiation budget at top of atmosphere (TOA). The annual global means radiation budget of this simulation at TOA is larger than the estimations (-17.0 Wm-2) came from Earth Radiation Budget Experiment (ERBE). The work showed the surface negative effect with -18.6 Wm-2 in the two different simulations of CRF. Otherwise, sensible heat flux in the simulation shows a great contribution with positive forcing of +24.4 Wm-2. It is found that cooling effect to the surface temperature due to radiative role of clouds is about 7.5℃. From this study it could make an accurate of the different CRF estimation considering either feedback of EXP-B or not EXP-A under clear-sky and cloud-sky conditions respectively at TOA. This result clearly shows its difference of CRF -11.1 Wm-2.