Abstract: Water-retaining agent be used to prevent and control the soil loss becomes a new research domain of the water and soil conservation branch，but still lack systematic research at this aspect at present。In order to avoid applying it blindly, the paper select 20 kinds of water-retaining agent of home and abroad，measure their absorb character through experiment，then choose the more suitable product for preventing and controlling the soil loss。The experiment result shows：the absorb water speed sequence of ABD type Super Absorbent Polymer is:ABD4