Abstract  For a long time, there have been heated arguments concerning the sedimentary environment of the Upper Ordovician Wufeng Formation in southern China. There are two opposite viewpoints: the deep water origin theory and the shallow water origin theory. It seemed that these two viewpoints both can negate the other one with ample evidence. The focus of the problem is related with the Guanyinqiao Member. According to the depositional characteristics of the Wufeng Formation, it should belong to a deep water deposition. But the Guanyinqiao Member at the top of the Wufeng Formation contained abundant fossils of Brachipodas, Trilobites, Corals and so on, thus it was considered as a “shallow water shelly facies” for a long period. Through measuring and detailed observation of tens of profiles in the Mid-Upper Yangtz area, it is concluded that the Guanyinqiao Member was deposited in a deep water allogenic environment. The evidences mainly include: the typical shallow water biologic fossils being contained in the Guanyinqiao Member such as the corals, echinoderms and brachiopods were preserved in the bioclastic calcirudite limestones in broken pieces. The overlying and underlying strata of the limestones were black graptolite shales, which was obviously transported by the clastic debris from other places and its sedimentary environment was not a shallow water environment but a deep water one. The Guanyinqiao Member is widespread with a very small thickness, which is not characterized by any shallow water deposition. The boundaries between the Guanyinqiao Member and its overlying Lower Ordovician Longmaxi Formation and underlying Wufeng Formation shales were inconsistent and changed sharply indicating the inharmonious deposition and was the characteristic of allogene deposition.. The Guanyinqiao Member only existed in the events deposition affecting range, in other areas, the Wufeng Formation can connect continuously with the overlying Longmaxi Formation. The deep water allogence deposition includes debris flow deposition(calcirudite), turbidite deposition(slity grain limestone) and internal-tide deposition(laminated siltstone). Regardless of the interpretation of the environment, the Wufeng Formation was determined as a deep water deposition due to its own characteristics.