The blast hole has a space between explosive and hole wall, and blast forces reaches the hole wall face with a large amount of loss during passing through this space. The loss ratio of blasting forces are different to this packing material of space like air, water, etc. In this study, the effect of packing materials is investigated by the numerical simulation analysis. The simulation is carried out to two phases; 1st phase is to compute the impacting forces reaching on the wall face passing through packing materials(air, water), 2nd phase is to study the blasting effect(block size of cracking, direction of driving forces, etc.) in real site. The reaching force at the wall face in the water is larger than in the air. This study shows that the water as packing materials is superior to the air.