Abstract: Through core observation in Futai oilfield, we describe the geometric characteristics, filling characteristics and mechanical properties to conduct research on various parameters of fractures. The results showed that a great amount of structural fractures was developed in Futai buried hills, which formed two directions. One was NE-SW and NW-SE direction conjugated shear fractures that were dominant, another was nearly E-W. Fractures were mainly vertical ones with the characteristics of E-W shear fractures. The core fracture openings which were mainly half filled with calcite were mainly distributed in 0.6~0.8 mm. Its average volume density was between 5~10 m²/m³, and fractures developed much more in northern part than southern of Futai oilfield.