An explosion is defined as a large-scale, rapid and sudden release of energy. Explosions, such as a bomb explosion within or immediately nearby a building and a gas-chemical explosion, can cause catastrophic damage on the building's frames, collapsing of walls, blowing out of large expanses of windows, and shutting down of critical life-safety systems. In fact, an explosion may result in large dynamic loads, greater than the original design loads, of many structures. Blast phenomenon and blast efforts have been made during the past several decades to develop methods of structural analysis and design to resist blast loads. The analysis and design of structures subjected to blast loads require a detailed understanding of blast phenomena and the dynamic response of various structural elements. This paper introduces different methods to estimate blast loads, also presents a comprehensive overview of the effects of explosion on RC structures.