Abstract: In order to understand the combustion performance of semi-coke of lignite from Shengli coal mine in Inner Mongolia,based on lignite assay,the semi-coke is produced under different pyrolysis temperature,what’ more effect of different pyrolysis temperature on performance of semi-coke is analyzed,with study of the characteristics of mass loss of combustion by thermogravimetric analysis. The result shows that yield of semi-coke is subject to pyrolysis temperature; with increasing temperature,the yield is lower; during 400-600 ℃,intense combustion reaction happens to semi-coke,however,with the increase of combustion temperature,combustion weight loss value of semi-coke decreased,and then the best combustion performance is obtained at pyrolysis temperature of 500 ℃.