Abstract: Based on the thermogravimetry analysis of typical small particle size long flame coal,effect of pyrolysis temperature on product yield and quality were researched using 1kg external- heated equipment. The results showed that semicoke yield decreased and coal gas yield increased as the final pyrolysis temperature rised from 500 ℃ to 750 ℃. The proportion of H2 continuously increased with the highest of 44. 64%,the change of CH4 was opposite with the value of 28. 83% to 38. 55%. The coal tar yield rose first,then fell,it reached the maximum at 700 ℃. Particle pulverization happened during pyrolosis,and reinforced obviously when the temperature was higher than 650℃. The suitable pyrolysis temperature ranged from 600 ℃ to 700 ℃ for small size Shenmu coal.