The oil shale dump in Maoming, Guangdong, formed by a process of oil shale excavation, separation, combustion and refining, is a huge man-made degraded ecosystem, up to 667 hm². The soils in the oil shale dump, mainly composed of a mixture, including oil-refined shale and surface soil coming from the oil shale mine, is extremely dry, infertile, and somewhat toxic resulted from heavy metals. After an 20 years' natural succession, there have colonized only 66 species of vascular plants belonging to 24 families and 59 genera on the completely barren oil shale disposal soil. Among them, 67% of total species and 80% of total coverage are made up of Poaceae, Cyper-aceae, and Compositae. The community construction and the composition of species are very simple and still in the early stage of secondary succession. This dictates that the natural vegetation in the secondary bare land piled by oil shale residue was rather slow. So it is necessary to add up artificial measures to speed up the vegetation restoration for mitigating pollution and improving the environment.