Determining radiative areas of geostationary satellite are one of the challenging tasks for satellite thermal engineers at the early stage of the project. Radiative areas of geostationary communication satellite for the payload and platform panels are determined based on worst hot case (end-of-life). After calculation of radiative areas, it needs to be optimized according to worst hot and cold scenario at sun acquisition mode, orbit raising mode and geostationary orbit. Authors, in this study, optimized geostationary satellite platform panel. The radiator's dimensions were calculated and then optimized based on sun acquisition mode, orbit raising mode and geostationary orbit. Determining radiative areas of GEO satellite is important task. Radiative areas always are determined based on hot case condition at EOL. On the other hand, these radiative areas needs to be optimized according SAM, ORM, and GEO scenario. Calculated radiative areas both the north panel and the south panel was 1 m 2. Radiative areas were studied at +/-10% m 2. It was seen from the analytical results that the surface temperature of the platform panel areas were between-48.5 o C at 1.1 m 2 of radiative area and 37.7 o C at 0.9 m 2 of radiative area.