Abstract: Pyrolysis chars were prepared at rapid heating and pyrolysis pressure from atmospheric pressure to 3 MPa using a liquid phase carbonization coke (petroleum coke) as raw materials.The effects of thermal history and pyrolysis pressure on the weight loss, BET surface area and CO2 gasification activity of petroleum coke were investigated. The following results were obtained at the rapid heating and pressurized pyrolysis: with the increase of the thermal history, the weight loss of liquid phase carbonization coke increased, its BET surface area presented a descendent trend, and its gasification activity decreased slightly; with the increase of the pyrolysis pressure, the weight loss of liquid phase carbonization coke increased, its BET surface area initially increased and then decreased, and its gasification activity was changed slightly and even unchanged. Besides, the gasification activity of liquid phase carbonization coke at the pyrolysis of atmospheric pressure was distinctly higher than that at the pressurized activity.