Abstract: Defferential Thermogravimetry, Thermogravimetry characteristics of single coal were studied and mathematical model for predicting combustion behavior of coal blends was established. The results show that DTG curve of single coal displays one peak and the peak temperature, tmax, relates to the fuel ratio F of the coal: tmax=68.86 ln（F）+512.2 (℃). The characteristics of DTG curves of coal blends can be obtained from that of single coal, which can be used to predict its combustion behavior. If the quality parameters of the coal blends meet the needs of the normative coal, its combustion behavior is good when Fmax/Fmin<3.20; it is middle when 3.205.70.