Abstract:Abstract: Dynamic derivative equations were built by Hamiltonian principle for a horizontal spinning beam. The cantilever beam was discretized by second-order central differences, and difference equations of free vibration were developed. A MATLAB Vibration Toolboxes program was introduced with damped vibration theory, and dimensionless natural frequencies were derived in different rotational speeds. Finite difference methods are proved effective by results comparison with references, and free vibration characteristics on uniform beams are analysed and optimized .Numerical analysis of free vibration are also made on free-free and clamped- clamped beams.