Abstract: Since pocket damper seals can efficiently weaken the circumferential velocity of the leakage flow, they endow rotors with excellent dynamic characteristics, as illustrated here. The research and development of pocket damper seals is presented at first. Investigations on the leakage flow and rotordynamic characteristics of pocket damper seals using theoretical analysis, experimental measurements and numerical predictions are detailed summarized. Two kinds of experimental methods, i.e. system impedance method and cavity dynamic pressure response method, for the measurement of rotordynamic characteristics of pocket damper seals are elucidated as well as their applications. Finally, the research and development of pocket damper seals for advanced turbomachinery design are briefly outlined.