The structure damage detection method uses the changes in dynamic parameters between the intact and damage states to evaluate and localize damage directly, fast and inexpensively. This paper adopted the curvature mode shape to investigate the damage in frame structure. The Finite element analysis was used to obtain the displacement. By using the central difference approximation, the curvature mode shapes were then calculated from the displacement mode shapes. Numerical simulation results show that the changes of curvature mode shapes are sensitive to the damage in the frame structure. Thus, the curvature mode shapes can indicate the presence of damage and its severity, and locate damage at the same time. Curvature mode shape is also suitable for detection of multiple damages. The experimental result further verifies its sensitivity to structural damage.