Abstract: The method for developing life cycle inventory of ethylene production was introduced，and the life cycle inventory was compiled. The life cycle consumptions of raw coal，crude oil and natural gas of unit ethylene production were 85.60 kg/t，2302.56 kg/t and 162.21 m3/t respectively, and the life cycle emissions of CO2，SO2，NOx，CO，ethylene and dust were 2 257.04 kg/t，8.93 kg/t，11.60 kg/t，7.62 kg/t，2.90 kg/t and 5.84 kg/t respectively. The direct emissions of ethylene production was the main source of the life cycle emission of ethylene，CO，dust and NOx. The CO2 direct emission and indirect emission was equivalent with each other basically; while the life cycle emission of SO2 mainly came from the stages of fuels production and transportation.