Based on available new geological-geophysical data, it is suggested that Nanpoyang Depression is characteristic of a texture of superimposed basin with pull-apart structure in the upper part and compressed structure in the lower part. The lower part is a nappe which overrides southwards. The Xiangtang-Erjiachun ramp zone in the southern part of the Depression is caused from ramping of the nappe on the north with the Guanmaoshan thrust system on the south, in which the upper Paleozoic hydrocarbon-generating and -accumulated rocks are preserved well. The internal structure of the ramp zone shows a banded remnant syncline or local overlapping thrust sheets caused typically by Jiuling nappe system. In fact, the nappe in Nanpoyang Depression belongs to same tectonic system with well-known Jiuling nappe system for it extended eastwards from Jiuling Mountain and joined with Gaotaishan thrust system in the east of Boyang. It napped during the middle Yanshanian orogenic movement (J3-K1).