Abstract: This paper introduces the technical progress of membrane separation for volatile organic compounds (VOCs). The basic principles of membrane separation technology for recovering butene and iso-pentane from VOC/ N2 are described, and the influence of operating condition on membrane separation is indicated. Recovery of hydrocarbon from VOC/ N2 could reach about 80% after putting the membrane separation unit in service. The permeate gas is then compressed and condensed for further recovery. Field application indicates that obvious economic benefit is achieved by low investment, clean production and high effectiveness of membrane separation.