Abstract: Reaction-regeneration″technology,which is similar with that of FCC,is used in heavy-oil contact cracking(HCC)process for producing ethylene.Heavy oil is di-rectly cracked to produce ethylene with byproducts of propylene,butylenes and light aromatic hydrocarbons.It can not only widen the source of raw materials but also lower production cost.The rate of recovery of ethylene can be up to19-27%,while that of total light hydrocar-bon over50%.