Abstract: With the laboratory experiments of the saltwater and the freshwater replacing each other in the level sand-column,and taking the kaolin,illite,smectite,bivalent mercury ion (Hg²⁺) and the phenol (C₆H₅OH) as the examples,this article studies the water sensitivity characters of the powder-silver sand.The results show that the influence of the content of the kaolin and illite on the water sensitivity of the powder-silver sand is very slight,which results in the descense of only one grade even the content reaching 10%(weight ratio); but for the smectite,it causes the hydraulic conductivity descending sharply by above-grades when its content reaches 3% (weight ratio),and without water flowing through the sand columns at 4% (weight ratio).With the effect of the shearing force from high speed fluid,the removing rate of Hg²⁺ ion and phenol (C₆H₅OH) is 31.68% and 55.71% respectively.And the remnants can be hold out of the powder-silver sand columnswith the particle's release and migration in water sensitivity process.The reason for the obvious difference between removing rates of two kinds of pollutants is that there are many negative charges on the particles surface which absorb the bivalent mercury ion (Hg²⁺) which makes its resorting rate is higher than the phenol (C₆H₅OH).So,we can make good use of the water sensitivity character of the powder-silver sand to build the impenetrable purdah and remove pollutions of the heavy metals and organic pollutants in the sand aquifer.