Rapid development of engineering activities expands variety of rock engineering processes such as drilling, blasting, mining and mineral separating. These activities lead to employment of rock dynamic fracture mechanics methods. Drilling operations and rock cutting processes normally follow with crack growth mechanism in rock mass. Fracture mechanics properties of rock play an important role in crack growth behavior in fractured layers and rock masses. Explosion, being used in mines to break rocks and excavate underground spaces, makes mine one of the most dangerous workplaces. Fall or throw of rocks are frequent in the mining environments and by increasing excavation depths, rock explosion phenomenon might occurs. The behavior of rocks under different loading conditions and the nature of fractures propagation in rocks can accelerate these phenomenon and increase costs. In order to ensure safety against dynamic forces, knowing the breaking mechanisms and effective factors of failure are essential. This paper attempt to present dynamic fracturing of rocks and its effective parameters, experiments are used to determine the parameters of dynamic fracture, required equations to compute them and effect of loading rate on the dynamic fracture toughness. This followed by experiments with Split Hopkinson Pressure Bar apparatus and the results of tests are examined to determine the dynamic fracture toughness of rocks.