Skin, gill and intestinal epithelial cells were developed using primary cultures of mucosal cells （isolated from healthy Nile tilapia） to study the adhesion of Aeromonas hydrophila to fish epithelial cells and the effects of Cu beating montmorillonite （Cu-MMT） on the adhesion of bacteria and on cell membrane injury due to Aeromonas hydrophila. The three primary-culture cells are susceptible to Aeromonas hydrophila attachment, with the greatest binding affinity found in gills, and to a lesser extent, in skin and intestine epithelial cells. Cu-MMT significantly inhibited （P 〈 0. 05） adhesion of bacteria to skin, gill and intestinal epithelial cells. The cell membrane was injured due to Aeromonas hydrophila. The activity of cytosolic free calcium concentration and membranous phospholipase A2 were increased （ P 〈 0, 05 ） significantly. Cu-MMT can significantly reduced （ P 〈 0.05 ） cell membrane injury caused by the adhesion of Aeromonas hydrophila. Our study shows that Cu-MMT showed a strong ability to inhibition adhesion of pathogenic strains to fish epithelial cell and open the possibility of applying Cu-MMT in aquaculture.