Abstract: The cracking of ethylene as one of the major components of oil refinery over a bed of Binxian char and quartz, respectively, has been studied in a fixed bed reactor at temperatures between 850℃ and 1000℃ and atmospheric pressure. The results show that the conversions of ethylene increases with increasing temperature. The products of ethylene cracking are H₂, CH₄, C₂H₆ and C. The higher the reaction temperature, the more complete ethylene cracking and the more H₂ produced. The higher initial conversion rate of ethylene cracking at 850℃ to 950℃ is only observed over Binxian char but not on quartz and an empty reactor. This indicates a significant catalytic effect of Binxian char on ethylene cracking. Ethylene conversion decreases with reaction time due to carbon deposition on the char surface. The conversion of ethylene is 94% over quartz and in the empty reactor at 1000℃, suggesting that ethylene can completely decompose through thermal cracking without catalyst.