Constrained damping layer (CDL) treatment has been an effective way to suppress vibration level of various structures. by introducing this method into the vibration control system of electronic equipments, this paper firstly discussed the dominant mechanism difference between free damping layer treatment and constrained damping layer treatment, Then base on the constrained layer damping layout optimization method in the vibration system of a rectangle thin board like PCB, a series of experimental investigations were presented on the vibration response of printed circuit boards treated with partial constrained damping layers. as a result, it proves the CDL treatment having good effect on vibration response control of PCBs.