To provide a damping force adjusting structure for a hydraulic shock absorber, enabling to extremely lower the damping force of a damping valve in the condition of high damping force during high pressure when the moving speed of a piston reaches a fixed speed.

The damping force adjusting structure for the hydraulic shock absorber 10 uses the damping valve for controlling the flow of an oil liquid from one oil chamber to the other oil chamber to generate damping force. In a bypass line 60 which bypasses the damping valve to communicate both oil chambers with each other, a first blow valve 70 and a second blow valve 80 are arranged in series in sequence for blowing the pressurized oil liquid from one oil chamber to the other oil chamber. The first blow valve 70 and the second blow valve 80 are built up with each other in a separative manner. One spring 90 which supports the second blow valve 8 at its back face energizes the first blow valve 70 and the second blow valve 80 to their closed positions. At the closed positions, the pressure receiving area of the first blow valve 70 is set to be smaller than the pressure receiving area of the second blow valve 80, and the open limit of the first blow valve 70 is restricted.