The Helan-Chuandian N-S Tectonic Belt is a mantle transitional belt in China.The southern part,forming the Chuandian N-S Tectonic Belt,comprises several tectonic systems,each displaying different characteristics.The Chuandian N-S Tectonic Belt along the western margin of Yangtze Block is a strike-slip tectonic belt with a series of echelon left-lateral slip faults.The strike-slip fault systems experienced two stages of structural deformation:early NW-SE striking thrust faults formed under a NE-SW compression stress field,and later sinistral strike-slip structures formed along thrust faults under a NW-SE compression stress field.Mesozoic basins developed between the left-lateral slip faults.Sedimentary facies and paleocurrent directions indicate that basin development was controlled by the strike-slip faults.The oldest strata in the Chuandian N-S Tectonic Belt constrain its formation to early Mesozoic.In fact,The slip tectonic belt formed by clockwise rotation and north-directed subduction-collision of the Yangtze Block in Late Triassic-Jurassic.The strike-slip faults that developed within the belt also formed at this time. The Helan-Chuandian NS Tectonic Belt is a mantle transitional belt in China. The southern part, forming the Chuandian NS Tectonic Belt, comprises several tectonic systems, each displaying different characteristics. Chuandian NS Tectonic Belt along the western margin of Yangtze Block is a strike-slip tectonic belt with a series of echelon left-lateral slip faults. The strike-slip fault systems experienced two stages of structural deformation: early NW-SE striking thrust faults formed under a NE-SW compression stress field, and later sinistral strike -Slip structures formed along thrust faults under a NW-SE compression stress field. Mesozoic basins developed between the left-lateral slip faults. Sedimentary facies and paleocurrent directions that that basin development was controlled by the strike-slip faults.. The oldest strata in the Chuandian NS Tectonic Belt constrain its formation to early Mesozoic. In fact, The slip tectonic belt formed by clockwise rotation and north-directed subduct ion-collision of the Yangtze Block in Late Triassic-Jurassic. The strike-slip faults that developed within the belt also formed at this time.