In this study, two simulation toolkits including Geant 4 and MCNP-CP are used to investigate the configuration of the Compton suppression spectrometer at Nuclear Research Institute. The Compton suppression system consisting of 12 bismuth germanate (BGO) scintillation crystals surrounding one HPGe detector is used to reduce background from Compton scattering. The simulation results illustrate the good suitability between response functions for point source with each radioisotope such as Moreover, the difference between the fullenergy peak efficiency of two simulation toolkits is less than 1%. This research gives the initial results to optimize the configuration of Compton suppression system and to compare with experimental data in the future.