A novel triaxis microgyroscope is proposed. Three orthogonal axis angular rates for pitch, yaw, and row can be detected simultaneously by the presented microgyroscope. The coupling effect of the triaxis angular rates due to Coriolis response and nonlinearity of the high-frequency modes can be efficiently reduced by the decoupled mechanical structure design. First, a 8×8 linearized state-space representation with a “holonomic” constraint is established and the relative stability of the dynamic system is investigated. Second, the mathematical description and discussion upon performance indices for a microgyroscope, such as sensitivity, bandwidth, and resolution, are addressed. In addition, the quality factor is verified to be a significant design parameter for microgyroscopes. The performance and stability of the gyroscope could be degraded by choosing inappropriate quality factors. Moreover, the trade-off among performance indices for the gyroscope is theoretically evaluated and discussed. Finally, in order to meet most performance specifications, a pole/zero mapping design method is proposed to satisfy either large bandwidth or high-resolution requirements.