Abstract: Numerous unconformities occur in the Neoproterozoic-Cenozoic cover sequence at the northeast margin of the Tarim Basin. They are the products formed under different geodynamic settings and provide important clues to the study on the tectonic evolution both at the northeast margin of and of the whole Tarim basin as well. Based on field geological survey and comprehensive study of the seismic materials of the basin, the authors further elaborate the features of the important unconformity interfaces of Nh₂/Nh₁，∈/Z ，O₃/O₂，S/O₃，C/AnC，T/AnT，J/AnJ，E/AnE，N₂/N₁ and their geodynamic background and try to set up a complete evolution sequence of unconformities in the area. According to the features of the unconformities，strata ,deposit and structure, the tectonic evolution of the covers at the northeast margin of Tarim basin can be divided into three cycles and six stages. The three circles are: the Nahuaian-Devonian intra-craton disintegration and closure, the Carboniferous-Triassic circum-craton disintegration and closure and the Jurassic-Quaternary pull-apart and compression. The six stages are: Nahuaian-Ordovician intra-craton aulacogen, Silurian-Devonian compression and uplifting, Carboniferous-Permian intracraton subsidence basin, thrust-strike-slip of the last stage of Lower Permian-Triassic foreland basin, Jurassic-Paleogene fault depression and down-warped basin and Neogene-Quaternary regenerated foreland basin stages.

Key words: northeast margin of Tarim Basin, unconformity, tectonic evolution