Abstract: The coal rock and its marceral six series of samples were conducted a thermal simulation experiment.The temperature was programmed from 250 to 550℃ with a temperature step of 50℃.The gas products were analyzed systematically.The results show that the gas production rate is increasing with temperature for the coal rock and its marceral,is varied at the same temperature for different simulated material,and is different under various temperature for the same simulated material.It is also revealed that the vitrinite and exinite have stronger gas potential,the gas production of the fusinite and semifusinite is very low,and the bulk coal samples display the synthetic hydrocarbon-generating effects of each marceral.CO₂ and N₂ make up larger percentage in the gas products mainly within low temperature bands.