Terrorist attacks are caused collapsing of many building in the world. A terrorist attack usually shows itself with an explosion of blasting agent or bomb which can cause catastrophic effects on buildings, roads, environments and people. An explosion can damage a building badly, it can collapse walls, spall columns, beams and blows windows out. So it can be say that the detonation of blasting causes many economical and life losing. Briefly, structural response of buildings has to be investigated against to explosives inflicted to a bomb or other blast agents to avoid this losing. So, this study investigates the structural response of buildings under blasting effects through a numerical evaluation. For the purpose, two-storey reinforced concrete (RC) building is analytically modeled in ANSYS Workbench software considering RC columns, beams, floors as structural elements and walls and windows as non-structural elements. Then two tons of TNT as blasting is defined in the building and it is exploded for 3 micro-second. This explicit analysis is performed using ANSYS AUTODYN software which is often used to simulate the response of materials to short duration severe loadings from impact, high pressure or explosions. The deformed shapes, pressure values and damage ratios are presented with contour diagrams as results of explicit analysis. The results shows that the blasting is so affected to structural response of the building