The average sulfur content of Tabas coal contained in the Parvadeh coalfield is approximately 1.5%. For the purpose of the conduct of the desulfurization program, a sample of high sulfur coal has been used. The coal was subjected to desulfurization tests using Thiobacillus ferrooxidans (DSM 581) in two different media and then was characterized using infrared spectroscopy. The reduction in total sulfur content was measured using a Lecoanalyzer. The results indicate that the reduction in sulfur content depends on the media employed. Fifteen days following inoculation, the pyritic sulfur was reduced by 59.8% in medium 9/10K and by 65% in medium TB.