Abstract: Using new digital lazar dynamic caustics system,the dynamic fracture behavior of semi-circular specimen containing empty holes subjected to impact loading was studied.The results show that,under dynamic impact loading,the stress concentration at the tip of edge cracks was greater than that at empty holes;when the empty holes were in front of running crack,the empty holes made the crack propagating velocity decreased,which decreased with the displacement between empty holes and the tip of edge cracks increasing;when the crack propagated again,compared to the crack propagating velocity and stress intensity factor at coalescence time,the crack propagating velocity for specimen S1,S2 increased by 1070%,138%,respectively,stress intensity factor for specimen S1,S2 increased by 61%,67% respectively;the dynamic stress intensity factor was po sitively correlated with the crack propagating velocity,but the stress intensity factor increased before coalescence time because of the empty holes.