Abstract: The new digital laser dynamic caustics testing system, together with hammer-drop test platform, was put into testing the dynamic fracture behaviors of materials with different defects.The results showed as following:defect structure attribute had little effect on fractures morphology of specimens and initial cracking, but it did prevent the extension of the crack process, which is prevented more through hole-defected materials than crack-defected materials.Moreover, as with crack velocity and dynamic stress intensity factor, non-defected materials were the same as crack-defected materials but different with hole-defected materials.