Abstract: As oil exploration and technique development progressed rapidly, fractured reservoirs play more and more important role in oil and gas production, and the knowledge about fracture permeability of liquid becomes more clear. Fractured reservoir is very complex and very difficult to be evaluated. There are many obstacles in the quantitative prediction of fractured reservoir, mainly because of highly anisotropic distribution, complicated origin, and multiple-staged development of the fractures. According to the theory of brittle fracturing and progressive deformation of rocks, this paper indicates the possibility of quantitative prediction of fracture development theoretically. Based on outcrop and core fracture data, taking that the fracture density in rocks is determined by the strain as the premise, after structure curvature analysis, theoretica1 numerical calculation of elastic strain energy, and analysis of fault-fracture relationship, the fracture density is estimated quantitatively in Qiuling oil field. The result of prediction shows that the fracture density in the west and central parts is m ore developed than that in the east, north and south flanks in Qiuling oil field. The predicted value of fracture density almost coincides with the measured value in well No.24 and 25. Furthermore, the reliability of the prediction result is evaluated preliminarily.