Abstract: The behaviour of absorbing nitrochlorobenzene (NCB) by the Yellow River sediment is investigated.With the stat experimental,the result of the experimental study about the sediment shows that about two hours is required for the sorption equilibrium.Furthermore,the mechanism of the absorption and the factors controlling the organic substance absorption from the sediment are studied,including the sediment concentration,pH,and the ionic strength.It is concluded that the adsorbent amount increases with the absorbent equilibrium concentration,and decreases with the sediment concentration.Under the experimental condition,the adsorbent amount of NCB decreases with the increase of pH and increases with the ionic strength.