Abstract: The aim of this project is to study the combustion characteristics of oil shale semi-coke. The oil shale sam-ples from Huadian, Longkou and Yilan were pyrolyzed in a tube furnace at the temperature between 450 ℃ and 600 ℃ ,then the semi-coke samples were analysed by thermogravimetric analyser at the heating rate of 30 ℃ / min. The influence of pyrolysis temperature and pyrolysis time on composition and calorific value were investigated. The re-sults show that a longer pyrolysis time has no obvious effect on composition and calorific value especially at higher temperature. After pyrolysis,the ash content increases while the volatile content deceases,and the calorific value chan-ges differently according to the origin. Higher temperature makes the ignite point Ti increase and the combustion char-acteristics of semi-coke become worse. The mass loss starts at 350 ℃ ,and decreases at 500 ℃ ,and there is an in-crease at 700 ℃ .