Some or the parameters affecting the thermal analysis of different types of ground tobacco have been discussed. The sample, Korean flue- cured and burley and Greek orient tobacco leaves were run in air at heating rate of $10^{circ}$ and 20^{circ}C$</TEX> per minute. The thermograms obtained were divided into four temperature zones. The effect of different heating rates on thermal degradation has been discussed At the lower heating rate the maxima of DTA curves in zone 3 and 4 were 25-$40^{circ}C$ lower than that of the higher heating rate.