The gas reservoir of deep Xujiahe Formation in western Sichuan Depression is a typical fractured gas reservoir, which is characterized by deep-buried, extra-high pressure, extra tight, low porosity and permeability. Fracture detection is one of the technical difficulties. Aiming at the problems, the authors studied the curvature attribute that is a practical seismic attribute. The curvature attribute was applied on the fracture detection in XC Block of Xinchang area, western Sichuan Depression. The result is coinciding well with drilling data.