The traditional definition of fracture azimuth and fracture dip can not fully and expediently reflect the effect of fracture anisotropy on fluid diversion. By analyzing results of this effect, the authors made a new definition for fracture azimuth and fracture dip, and on the basis of this definition, a new approach was proposed to calculate anisotropic parameters of fracture permeability. The dynamic effect of fractures on fluid diversion together and makes up a limitation of the current method in describing and calculating the permeability of fractured reservoirs.