Abstract: The Longmen Shan fold and thrust belt is a key region for the study of Meso-Cenozoic tectonic evolution of the China continent．This belt experienced at least two major tectonic events of the Late Triassic an d Early Cenozoic ages，and formed obviously two phases of the foreland basin and the foreland fold-thrust belt．In this paper，the structural features of the Longmen Shan fold belt are presented ，with both tw-dimensional seismic profiles and field data．The complex structures of the NE trending Longrnen Shan fold—thrust belt and its foreland in the western Sichuan basin are interpreted as being formed by southeast-directed thrusting．The wedge-shaped Longmen Shan belt，consisting of numerous thrust sheets and nappes，thrust over the western side of the Yangtze craton．In both structural geometry and relative timing of folding an d thrusting, the northern Longmen Shan is significant different from the southern Longrnen Shan．The Longmen Shan fold and thrust belt can he divided into two major segments：the northern Longmen Shan an d the southern Longrnen Shan ．Several eastward-verging，rootless thrust sheets and imbricates of the Cambrian-Triassic rocks have been recognized in the northern Longrnen Shan ．Evidence suggests that the northern Longmen Shan experienced two periods of major deformation in the late Triassic an d Cenozoic ages ，though the late Triassic deformation is mole significant than the Cenozoic．Farther south，these principal tectonic units in the southern Longmen Shan are represented by the basement—involved thrust structures ，and the frontal thrust structures Propagated east-ward and actually passed from the edge of the thrust belt into the foreland of the western Sichuan basin．Its major deformation started in the Late Cretaceous-Early Cenozoic and continues to the present． Contemporaneous with thrusting was the development of the western Sichuan foreland basin．Sedimentary features of the foredeep exhibit two-phase flexural loading occurred within the western Sichuan basin，an d suggest that the Late Triassic peripheral foreland basin extends along the foredeep of the Longmenshan belt，but the Late Cretaceous．Paleogene rejuvenated foreland basin is restricted in the southern part of the western Sichuan basin．