Objectives:The Langshan Group is an important Precambrian stratigraphic unit in northeastern Alax Block, which documented complicated evolution histories. Some geochronological data suggested that the depositional age is Neoproterozoic, but it is unclear about the tectonic evolution and deformation history of Langshan Group. Therefore, more detailed researches on this Group are vital to reveal the tectonic evolution and deformation history. Methods:In this study, the deformation of Neoproterozoic Langshan Group outcropped in southwestern of Langshan area was summarized. According to the tectonic mapping and geological section, three deformation stages in Langshan Group were identified. Results: The earliest deformation caused isoclinally overturned folds. The deformation of the second stage was the nearly east—west trending dextrally ductile shearing. The last deformation was caused by the sinistrally ductile shearing of the Langshan—Bayanwulashan Fault. Combination with previous studies and geochronological data in this region, the authors suggested that the NEEtrending and EWtrending isoclinal overturned folds in Neoproterozoic Langshan Group was caused by the closure of the PaleoAsian Ocean along the Enger Us suture zone in the late Paleozoic, which led to nearly north—south trending compression. In the end of late Paleozoic—early Mesozoic, Langshan area was cut by a dextrally ductile fault which may be the intraplate adjustment after the PaleoAsian Orogeny. The early EW trending folds turned to NEtrending due to the sinistral ductile shearing during the Middle—Late Triassic. Conclusions:Langshan Group experienced three main deformation stages, including: nearly north—south trending compression in the late Paleozoic, nearly east—west trending dextrally ductile shearing in Paleozoic—early Mesozoic and NEtrending sinistral ductile shearing during the Middle—Late Triassic. Combination with previous studies and geochronological data, we suggest that the subduction of the PaleoAsian Ocean on the north margin of Alax Block was after early Carboniferous. Those deformation established the basic structural patterns in the Langshan region.