The finite element modeling of the truss structure in ANSYS software is considered. The problem of the identification of defects in the truss rod construction was considered on the base of an analysis of the parameters of the vibration modes. A truss rod construction with two defects was modeled. The deflection and curvature of the vibration modes are analyzed. Defective elements are represented in the form of a change in the construction parameter of cross-section, localized in the vicinity of one of the junction nodes of the truss and fastening the rod. Modal analysis of the structure is carried out. The dependence of the eigen-frequencies and parameters of the vibration modes on the magnitude of the defect is considered. The analysis shows that the modal identification signs allow us to identify the defective node in the construction.