Abstarct: Nowadays, underground spaces are important in transportation, military and industrial applications. Drilling and blasting are two usual techniques in underground spaces drilling. Efficiency and drilling costs are controlled by rock properties, explosives and generally blasting pattern. Rock-mass contains some discontinuities which are really effective in blasting process. To distribute blasting holes baxsed on the discontinuities, designing a three dimensional model of rock-mass can be proper and helpful. In this thesis, a novel technique is proposed by considering the rock-mass discontinuities and conventional methods. Then in the first step, necessary data of tunnel face geometric are provided using 3DEC and UDEC softwares. In the second step, blasting holes distribution code is prepared baxsed on center block and maximum dimension with MATLAB software. Finally, the presented code validation is performed in eastern Alborz coal mine and its fragmentation analysis is testified by Goldsize software