The dynamic properties of multi-walled carbon nanotubes (MWNTS)/epoxy nanocomposite beams were investigated experimentally and numerically. The MWNTs/epoxy nanocomposite beams were fabricated by hot press method. In experiment, the dynamic properties of the nanocomposite beams, such as natural frequency, and damping ratio, were obtained. A shaker was used to provide the vibration source at the fixed base of the specimens. The vibration signals of the nanocomposite beams were detected by a laser sensor, and the frequency responses were obtained by a computer-aided signal analyzer. The half power method was used to find the damping ratios of the nanocomposite beams for each mode. In analysis, the mechanical properties of MWNTs/epoxy nanocomposites were obtained and used in the free vibration analysis by the finite element method. The natural frequencies and mode shapes of the nanocomposite beams were calculated numerically. The effect of the weight percentage of MWNTs on the dynamic properties of the nanocomposite beams was investigated. The numerical results were found to be in good agreement with the experimental ones.