Abstract: In this paper the nappe structure developed in southern Jiangsu is discussed.The Devonian strata rest on the Permian strata in many places of Taihu and Jiangyin areas, the paleozoic folds taking a shape of "sole"are overthrusted on the Late Jurassic volcanics in Maoshan moun-tain range, and the Pre-Cambrian strata of "Taizhou Buried Hill" are lying on the red beds of the Cretaceous.All these are evidence suggesting the multitype, multidirectional and multistage feature of the nappe structure. The nappe swarms in Taihu and Jiangyin areas are caused by the Kunjia block uplift and their roots are located approxima tely in Kunshan-Jiashan area.If the outcrops of the Devonian formation in Jingjiang and Nantong areas are also proved rootless, then the maxium displacement of the nappes will probably reach seventy five Kilometers.As nappe structures may act as barriers to oil and gas migration, their practical significance is as important as that of unconformity. In field and research work, attention should be given to identifying these allochthonous sheet-like blocks.