In this research effect of particle size on the combustion properties of Cayirhan coal sample was studied. Non-isothermal thermogravimetry and derivative thermogravimetry (TG/DTG) experiment were carried out for twelve different size fractions of the Cayirhan coal sample. Thermogravimetry experiments were performed from ambient to 900 degrees C in air atmosphere. Differential thermogravimetric data were analysed using an Arrhenius type reaction model assuming a first-order reaction. Kinetic parameters of the samples are determined and the results are discussed.