In computer graphics, the most challenging problem is modeling natural phenomena such as water, re, smoke etc. The reason behind this challenge is the structural complexity, as the simulation of natural phenomena depends on some physical equations that are di cult to implement and model. In complex physically based simulations, it is required to keep track of several properties of the object that participates in the simulation. These properties can change and their alteration may a ect other physical and thermal properties of object. As one of natural phenomena, burning wood has various properties such as combustion reaction, heat transfer, heat distribution, fuel consumption and object shape in which change in one during the duration of simulation alters the e ects of some other properties. There have been several models for animating and modeling re phenomena. The problem with most of the existing studies related to re modeling is that decomposition of the burning solid is not mentioned, instead solids are treated only as fuel source. In this thesis, we represent a physically based simulation of a particle based method for decomposition of burning wood and combustion process. In our work, besides being a fuel source, physical and thermal a ects of combustion process over wood has been observed. A particle based system has been modelled in order to simulate the decomposition of a wood object depending on internal and external properties and their interactions and the motion of the spreading re according to combustion process.