<p>Thermoelastic damping (TED) is the dominant intrinsic energy dissipation mechanism in micro/nano resonators, and accurate prediction of thermoelastic quality factor (<i>Q</i>_TED) is essential for performance optimization. This paper systematically investigates the vibration and<i> Q</i>_TED characteristics of annular plate resonators under various boundary conditions. Two analytical models for determining<i> Q</i>_TED, namely the frequency ratio and energy methods, are developed and systematically compared. Analytical solutions for the temperature field are derived using Bessel functions. The results demonstrate that the energy method significantly outperforms the frequency ratio method in prediction accuracy, particularly under inner-clamped and outer-free boundary condition. The present methodology is validated against finite element simulations, experimental measurements, and published literature, confirming its broad applicability across various thermal conditions and plate geometries. Parametric analysis reveals that<i> Q</i>_TED exhibits an inverse relationship with frequency and is highly sensitive to thickness variations. Material selection also plays a decisive role, with silicon yielding the highest<i> Q</i>_TED among aluminum, steel, and silicon. Designing annular plate resonators with small thickness, small inner radius, and large outer radius is an effective approach to enhance <i>Q</i>_TED. The findings provide important theoretical guidance for the design and optimization of high-performance annular plate resonators.</p>