Fracture system plays a very important role in the enrichment and accumulation of oil and gas in the reservoirs�� Based on scattering wave information�� Fracture Orientation Function (FOF) was built�� which can be used to predict the fracture orientations�� However��this method has only been verified by physical experiments without studies on the application scope�� In this study�� based on the linear sliding theory�� FOF of the scattering wave was applied to the numerical simulation and the application scope was further studied according to fracture flexibility tensor�� According to the fractures filled with gas and liquid�� numerical simulation was conducted on the models with various fracture flexibilities�� Numerical simulation results were used to inverse fracture orientation with the aid of the FOF of the scattering wave�� The results show that it is workable to predict the vertical fracture orientation with the FOF of the scattering wave�� Application of this method is more effective when the fractures are filled with gas than liquid�� Moreover��the application scope can be predicted by the fracture flexibility��