The present invention relates to a new shape of a shock absorbing guardrail to secure safety for passengers by absorbing shock when a vehicle runs into the guardrail in the traveling direction. For this, the present invention comprises a plurality of vertical frames vertically and separately installed on the ground in the traveling direction of vehicles; a horizontal frame to cross the front surface of each vertical frame in the traveling direction of vehicles; a guide frame on the front or rear surface of the horizontal frame in the longitudinal direction of the horizontal frame with the inside as an open pipe body; and a moving frame which is accepted in the guide frame to move along the guide frame and dampens shock caused by the collisions with vehicles by expanding the guide frame in the excessive insertion of the moving frame into the guide frame.
