Sponge is one of the most primitive multicellular animals in the world, which distributes widely on earth, from tidal zone to deep sea bed, even can be seen in fresh water. This article outlines the biological characteristics of sponge， including external features, internal structure, life habits and so on. The article also introduces the prospect of using the high efficiency pump function of sponge in purifying aquaculture water and as parts of the symbiotic system to prevent aquaculture disease.