One of the most abundant fossils of Gaojiashan Biota, Gaojiashania Yang et al., 1986, was originally described by Lin and Zhang (1986) from the Gaojiashan Member, Dengying Formation in the Gaojiashan section, Ningqiang County, southern Shaanxi. They are buried in situ, occurring in the siltstone and limestone. Gaojiashania is a straight or curved tube-like fossil composed of a series of ridges and rings. Most of Gaojiashania are three-dimensionally preserved and some specimens are preserved as membranes lying on the surface. The different appearance and character are assumed to be resulted from the diagenetic process and mineralization. Early diagenetic pyrite played an important role in the preservation of the fossils. The soft bodies of the fossils can be preserved, this suggests that the pyrite mineralization occurred very early in the diagenetic history of a fossil and prior to appreciable decay of soft bodies of the fossils. Exceptional preservation is due to rapid mineralization prior to decay. Gaojiashania was first described as worm and referred to annelids. The specimens are often three-dimensionally preserved and composed of a series of separate rings lined on the substrate. These features have not been known from any kind of worms and trace fossils. The Gaojiashania appears metameric and the rings as the hard parts of the body seem to have been biomineralized, perhaps had no relationship with the annelids.