Summary: The governing equations for linear vibration of a rotating Timoshenko beam are derived by the d'Alembert principle and the virtual work principle. In order to capture all inertia effect and coupling between extensional and flexural deformation, the consistent linearization of the fully geometrically non-linear beam theory is used. The effect of Coriolis force on the natural frequency of the rotating beam is considered. A method based on the power series solution is proposed to solve the natural frequency of the rotating Timoshenko beam. Numerical examples are studied to verify the accuracy of the proposed method and to investigate the effect of Coriolis force on the natural frequency of rotating beams with different angular velocity, hub radius and slenderness ratio.