During the last two decades structural damage identification has become an important research area for civil, mechanical, and aerospace constructions. A great variety of methods have been proposed for damage detection by using dynamic structure parameters. Most of them require modal data of the healthy state of structure as a reference. In the present paper an identification technique for damage detection which utilizes mode shape curvatures obtained from vibration analysis of damaged laminated composite beam is proposed. Since the present procedure uses only the experimentally measured natural frequencies and their corresponding mode shapes, high accuracy of the vibration sensing is needed for the modal data. Therefore the damage detection is preceded by an investigation of experimental errors influence on dynamic characteristics of a beam. Examples of the detection of damage introduced by low-velocity impact are described.