In this article, the recent and original results on the effect of thermoelastic damping (TED) on the vibrational properties of micro-and nano-mechanical resonators are reviewed. Thermoelastic damping is recognized as a significant loss mechanism at room temperature in micro-scale resonators. The thermoelastic damping theory was first presented by Zener in 1937, and recently refined by Lifshitz and Roukes. A review of the thermoelastic damping process is presented. Also the theoretical and experimental advances in this field are introduced and discussed. Finally, some results gained by the authors are presented.