Abstarct: Geometric characteristics of rock mass discontinuities are the most important factors influencing the flow rate of fluid (oil, water and gas), rock mass resistance and stability, as well as the penetration rate of the TBM machine. In many areas there is no possibility of harvesting discontinuities due to the absence of outcrops on the ground. In this case, the only way is to grasp the geometric information of the discontinuity network, to speculate in the region, and to examine the discontinuities deep in the earth. The specimens provide a lot of information for modeling, including slope and tilt direction (if not done geotechnically) and length of work. The main purpose of this dissertation is to estimate the geometric model of the rock mass discontinuity network baxsed on the minimum information obtained from the specimens, the linear density of seismicity. For this purpose, using three data points of Parsian Reservoir Dam, Karun 4 Dam and Azad Dam baxsed on the data of drilling and surface drilling data, modeling has been done in five levels of accuracy. For the modeling of discontinuities, at the first level, the general frequency of discontinuities and, at the next levels, in the next levels, are added to the abundance information of each joint, opening, slope and tilt direction, and surface information. The modeling validity percentage is baxsed on the comparison between the volume intensity of the discontinuities in the simulated model and the baxse model. The results show that by increasing the information gathered from the network of discontinuities, the modeling accuracy increases. The percentage of credibility of all three areas studied in the first stage is 51-54, the second stage is 63-65, the third stage is 56-88, the fourth stage 88-90, the fifth stage is 96-102. On the third level of simulation, the level of volume variation and model validity strongly increase with respect to the fourth level, indicating a greater sensitivity of modeling validity to the length of the discontinuity effect. Also, slope and slope direction will not have much effect on the volume of the model.