In this study, Fire Dynamic Simulator (FDS) has been improved with the implementation of marker particles. Convectional FDS is able to implement only two curved geometries, namely, circular cylinders and spheres. The introduction of marker particles made it possible to implement arbitrarily curved objects. Moreover, an algorithm that extracts the marker particle information from a model designed by AutoCAD was developed. With the present implementation, applicability of FDS is greatly enhanced, beneficial to both academia and industry.