Abstract: Damage detection methods based on vibration responses intensively interest relevant researchers. To ensure the applicability of these methods, it is important to study the sensitivity of dynamic properties to structural damage. For this purpose, this paper presents an analytic solution of dynamic properties of cantilever beams with certain damage. Based on this solution, the sensitivities of different dynamic properties to damage are discussed. It is observed that the natural frequencies and mode shapes do not change significantly when damage accumulates in one section of the beam; while the mode of rotation angle and curvature mode suffer abrupt change near the damaged region. These results and discussions could provide some references for the researchers working in this field.