Abstract: Xujiahe Formation in the fault-fold belt of central Yuanba area, Sichuan Basin is a low-porosity and low-permeability reservoir, where fractures have important influences on the accumulation and productivity of natural gas. Based on the field outcrop, core, logging, inclusion analysis, acoustic emission and (U-Th)/He dating, a comprehensive study is carried out on the formation stages of regional structural fractures. Research indicates the development of high-angle and low-angle shear fractures due to tectonic genesis, characterized by meso-scale, minor width (sealed), large spacing, low filling degree and good fracture effectivity. The structural fractures of Xujiahe Formation were formed in three stages (without considering the fractures in the diagenesis stage). Stage-1 structural fractures were formed in the middle late period of Yanshanian movement with NE (30°± 5°)and NW (315°±5°)trends; the fractures were highly filled by meso-fine-grained calcite, inclusion homogenization temperature was 75-85℃, and the maximum effective principal stress of paleogeostress was 18.8 MPa. Stage-2 fractures were formed in early-middle period of Himalaya tectonic movement with NEE (75°±10°)and SN (0°±5°)trends; the fractures were half-filled (or unfilled)with coarse-grained calcite, homogenization temperature was 150-175℃, and the maximum effective principal stress of paleogeostress was 27.9 MPa. Stage-3 fractures were formed in the late period of Himalaya tectonic movement with NWW (290°±10°)trend; the fractures underwent a low degree of filling, the fillings of Stage-1 and Stage-2 fractures were obvious before cutting, and the maximum effective principal stress of paleogeostress was 38.6 MPa. In combination with geomechanics theory, the genetic patterns for the development of three-stage fractures are established.