Abstract: Active constrained layer damping (ACLD) is an activedamping form that replaces the uncontrolled constrained layer ofpassive constrained layer by controlled piezoelectric materials and　actively controls the shear deformation of viscoelastic materials by　controlled constrained layer in order to enhance the energy dissipation　of vibration. It sufficiently combines the advantages of active control　and passive damping and reveals excellent application values on　structure vibration control. This paper explains the structure and the　operating mechanism of ACLD at first. And then, reviews the recent　researching progresses on structure modeling, control strategy and　structure optimization of ACLD etc. At last, indicates the future　application and summarizes the further studying problems.