Through thermal simulation of Selective Laser melting (SLM), one can predict the thermal distribution over the power bed during the process without performing practical experiments. In this case, the production of a piece can be improved and the possible failure in the final part would be prevented. In SLM there is high temperature gradient which leads to imposing thermal stress due to deformation and, finally, fracture of workpiece. The duration of simulation depends on several factors such as thermal properties (specific heat and thermal conductivity) of the material (constant or temperature dependent), scan area, meshing, number of laser scan tracks, and laser scan velocity value.