A software development of satellite attitude dynamics and control simulation is presented in this study. The software compromises two primary modules, 1). simulation and animation module, 2). operation module. It is developed in a PC platform by using C++ programming tool. The software development is intended to maintain generality to the extent possible through object oriented approach for future modification and expansion. Feedback attitude control using a reaction wheel assembly and open-loop control by multiple pulse thrusters are implemented in the S/W. The principal model and thruster control mode is taken from Koreasat 111 which is a geostationary satellite launched in 1999.