Abstract: The occurrence mode of chlorine in solid products from copyrolysis of coal and waste plastic was studied by IR and TGMS. In addition, the emission characteristic of those solid products during combustion was studied. The results indicates that when copyrolysis temperature is below 600℃, there are some organic as well as inorganic chlorine compounds in coke; when the temperature is above 600℃, there is only inorganic one in the coke. The emission ratio of chlorine is relative to combustion temperature, the copyrolysing temperature as well as the percentage of PVC. The emission ratio of chlorine increases with the rising temperature of combustion. When the combustion temperature is 900℃, the emission ratio is up to 94%. On the contrary, the emission ratio is lower for the solid product from higher copyrolysis temperature as the combustion temperature is the same. The highest chlorine emission ratio from pyrolysis at 400℃ is 99.86%, but that from 1000℃ pyrolysis is 94.35%.