In the current research, the natural frequency of a beam with a crack, is investigated numerically by finite part methodology victimization analysis software system ANSYS APDL 15.0. In this research” Vibration Analysis of Elastic Cracked Beam” the response characteristics of a beam is predicted for both intact and cracked beams. In addition to that the response characteristics for different crack depth were studied. Crack depth and location were main parameters for vibration analysis. So it becomes for very important monitor to change the response parameters of structures to access structural integrity performance and safety. To observe the effect of crack to the natural frequency of the beam. In the current work, the natural frequency of a beam with a crack, was investigated by finite element method using analysis software ANSYS APDL 15.0. Different crack depth effects were considered & the results are compared with that of the beam without crack. Theresults obtained from the vibration analysis of the beam show that the lowest fundamental frequency of the beam without crack was higher than the lowest frequency obtained for beam with cracks.