A numerical computation and experimental tests have been performed for the investigation of dynamic behavior of thick composite beams. The present finite element method can effectively evaluate transverse shear deformation by considering layer-wise in-plane displacements. The natural frequencies and damping values were measured by fitting the frequency response function obtained from FFT analyzer. The frequency-dependent damping properties of composite material were measured to utilize them for the finite element analysis of thick cross-ply cantilevered beams. The experimental results are in good agreement with those of finite element analysis.