In real condition the experimental study of scale on explosion resistance of reinforced concrete slab has highly expenses in conduction experiments. This analytical result of the work are overly desirable and close to the real time condition. This work indicates the obvious effect of scale on dynamic response resistance, stress strain behaviour, deflection of unilateral slab of reinforced concrete which are exposed to blast loading due to sudden explosion. To achieve this study reinforced concrete slab which were exposed to blast loading. Explosion test on this reinforced concrete slab which has different standoff distance. The slab are supported at its two ends using a suitable support condition. This work is analyze using the finite element software ABAQUS. The result of this experimental work is compared with the result obtained from the analytical result. From result the detachment in two slab of reinforced concrete both big and small is similar. The analytical behaviour of the slab is moreover same as that of the experimental behaviour.