Smoldering is a slow, flameless and the most persistent type of combustion. Wildland fire or ground fire is an example of smoldering combustion which has become one of the most important issue in Indonesia and no effective solution has been found to solve this phenomenon yet. The organic materials contained in peatland can potentially become a flammable fuel with the presence of a trigger for wildland fire. In this experimental work tobacco material was used to study smoldering phenomenon. The relation between material density with temperature distribution and mass loss rate are conducted in the experiment. The transmissivity of the smoke produced by the smoldering combustion will also be analyzed. Experiments are carried out for the material density ranging from 0.12 - 0.2?g/cm3. The result showed that smoldering combustion are affected by density, due to the allowance of airflow and heat propagation. The result showed that material bed with the lowest density of 0.12?g/cm3 has the slowest smoldering velocity and mass loss rate while the material bed with the highest density of 0.2?g/cm3 has the fastest smoldering velocity and mass loss rate. The smoke took a longer period time to reach the bed surface at higher bed density.