A slider touch-down preventing system for a head stack assembly, which includes a weight load to reduce the slider's movement; and a weight holder connecting with a suspension of the head stack assembly to hold the weight load. The weight holder is positioned at an opposite side of slider loading part of the suspension which has a structure to absorb vibration energy and is positioned beyond a middle portion of the suspension. The invention also discloses a HSA and a disk drive unit having such a slider touch-down preventing system.