The Insulation Performance of Compressed Gas Insulated Switchgear and Gas Insulated Transmission Line(GITL) systems can be substantially affected by the presence and movement of metallic particle contaminants. SF 6 gas is the main mode of insulation in Gas Insulated Substations(GIS). The voltage withstanding capability of SF 6 bus duct is strongly dependent on field perturbations. A method based on particle motion is proposed for determining the movement pattern of metallic particle in Gas Insulated Bus duct(GIB) by considering all the forces acting on the particle like gravitational, drag and the electric field forces. In this work, a single phase of GIB with inner and outer diameter to 55mm and 152mm is considered for the analysis and compared with a single phase enclosure with inner diameter of 70mm and outer diameter of 190mm. Electric fields at the instantaneous contaminated particle locations were computed using Charge Simulation Method (CSM). The simulation carried out for various bus configurations with aluminum, copper and silver wire like particles inside 100KV, 132KV, 145KV and 175KV class enclosure of GIB. The results of the simulation have been presented and analyzed in this paper.