Abstract: Tabei sag is congidered to be a compresso-shear compound sag with dual structures，which was a tensional one during pre-Triassic period or a compressional one during Triassic to Quaternary period. Echelon fractures and structures strlke NE in the eastern part and NW in the western part，Three major fracturs resulting from the three periods of tectonic movements are prescent on cach anticline，Anticlines in Taibei sag can be divided into four types: anticlinds of basement-convoluting fault，basement uplft，superifical decollement and differential compaction.Futhermore, faulting anticline can be subdivided into four sccondary typs: semi-fan fault-controlled anticline，convergence compound anticline，dislocation and divergence anticline, and overlapping anticline. The Jurassic at the center of the sag is the most praspective formation，next is adjacent area to oil ganeration sag followd by the front of foreland and local slope zone.

Key words: Turpan-Hami basin, Taibei sag, Tectonic framework, Jurassic, Hydroarbon evaluation