The ODA method (ODA, 1996) is usually used to charaterize 2-D (two dimensional) fractured flow media. Based on the method, a fracture is modeled by two paralel lines in 2-D flow media. Groundwater, petroleum fluid as well as hydrogeothermal fluid flow three dimensionalyl in the nature. They are controlled not by gravitation only, but also by geological structure, in term of fracture network. Accordingly, the ODA method has not considered the effect of 3-dimensional fracture network. This research is intended to be a starting point to extend the 2-D ODA method resulting the modified 3-D ODA method. The research results will be profitable for characterization of 3-D fractured flow media in the context of groundwater, petroleum as well as geothermal engineering. As the first start, the research will focus on mathematical modeling of 3-D fractured network.