Using X-Window system (Motif Graphic User Interface), the AKM (Apogee Kick Motor) firing software for Koreasat which will be launched in 1995 has been developed to transfer the spacecraft from its transfer orbit, provided by the DeltaII launch vehicle, into a nearly geostationary drift orbit. The AKM firing software runs in one of two modes. In mission analysis mode, using a fixed magnitude impulsive velocity change, it provides the necessary data for planning the burn parameters. In insert mode, it uses the orbit propagator function to integrate the spacecraft state through the AKM burn. In this case, an AKM thrust profile and specific impulse are applied to the necessary data for planning the burn parameters to obtain the best possible drift orbit. The apogee burn planning simulation for orbital transfer of Koreasat has been performed using the AKM firing software. And the result of this simulation has been analyzed.