Disclosed is a frequency sensitive type shock absorber including a piston rod reciprocating an inside of a cylinder and having a connection passage therein; a piston valve mounted on the piston rod and having a plurality of compression and rebound flow paths penetrating up and down thereof, and partitioning the cylinder into compression and rebound chambers; and a valve assembly mounted on the piston rod to generate a damping force that changes with frequency during a rebound stroke; wherein the valve assembly comprises: a housing coupled to the piston rod and having a pilot chamber in communication with the connection passage; a main retainer coupled to the piston rod and having a main chamber formed on an upper portion thereof in communication with the connecting passage; and a pilot valve coupled to the piston rod and disposed between the housing and the main retainer to partition the pilot chamber and the main chamber.

A damper assembly includes a pressure tube forming a chamber, a piston assembly disposed in the chamber and dividing the chamber into two subchambers, and a piston rod fixed to the piston assembly. The piston assembly includes a body having an inner bore extending axially through the body. The piston assembly includes a blowoff disc contacting the body at the inner bore and having a throughhole aligned with the inner bore. The piston rod extends through and concentrically contacts the inner bore and the throughhole. The body has a groove extending axially along a length of the inner bore. The groove and the piston rod form a passageway permitting fluid to travel across the body. The blowoff disc has a notch extending from the throughhole and arranged to permit fluid from the passageway to pass across the blowoff disc.