In this study the desulfurization of a high pyritic and high organic sulfur lignite taken from the Gediz area (western Turkey) was investigated by the oxydesulfurization method using ammonia solutions. The influence of such parameters as the concentration of ammonia solution, partial pressure of oxygen, temperature, and reaction time were studied. The ranges of these parameters were selected as 0-10 M concentration of ammonia solution, 0-1.5 MPa partial pressure of oxygen, 403-473 K temperature, and 10-60 min reaction time. It was concluded that the use of ammonia solution as an extraction solution increased the efficiency of the oxydesulfurization process.