In order to enhance the quality factor(Q) of micro-electro-mechanical system(MEMS) resonator, this paper proposes an energy-decoupling frame structure which is applied in an MEMS resonator for energy decoupling and Q enhancement. An aluminium nitride(Al N) piezoelectric resonator is designed to work at 30 MHz frequency(f) in the lateral-extension mode. The resonator Q is significantly enlarged to 4.3×10~4 and the value of f·Q reaches to 1.29×10~(12). The energy coupling between the resonator and the substra...