A new parallel Monte Carlo simulation method of secondary electron (SE) and back scattered electron images (BSE) of scanning electron microscopy (SEM) for a com plex geometric structure has been developed. This paper describes briefly the si mulation method and the modification to the conventional sampling method for the step length. Example simulation results have been obtained for several artifici al structures. A new parallel Monte Carlo simulation method of secondary electron (SE) and back scattered electron images (BSE) of scanning electron microscopy (SEM) for a com plex geometric structure has been developed. This paper describes briefly the si mulation method and the modification to the conventional sampling method for the step length. Example simulation results have been obtained for several artifici al structures.