This invention provides a micromechanical resonator oscillator structure and a driving method thereof. As power handling ability of a resonator is proportional to its equivalent stiffness, a better power handling capability is obtained by driving a micromechanical resonator oscillator at its high equivalent stiffness area. One of the embodiments of this invention is demonstrated by using a beam resonator. A 9.7-MHZ beam resonator via the high-equivalent stiffness area driven method shows better power handling capability and having lower phase noise.