Abstract: Olive pomace insoluble dietary fiber( IDF) was prepared by alkaline method with defatted olive pomace.In addition to its chemical composition and structure characterized by IR and X- ray diffraction,the effect of olive pomace IDF on the in vitro adsorption capacity of NO_2~-,Pb~(2+),Cu~(2+),Cd~(2+) was studied. These results showed that the IDF content in olive pomace IDF reached 90.09%,which was mainly comprised by cellulose,hemicellulose and lignin.The result of IR showed that olive pomace IDF appeared characteristics absorption peaks of sugars and lignin. The result of X-ray diffraction indicated that IDF had celluloseⅠcrystal structure,and its crystallinity achieved 47.94%.The quantities of equilibrated adsorption to NO_2~- using IDF under the simulated gastric condition( pH2) was attained 826 μg / g at 240 min.The adsorption capacity of IDF for Pb~(2+),Cu~2+),Cd~(2+) under the simulated intestine condition( pH7) was far stronger than that in the gastric. The equilibrated adsorption quantities for Pb~(2+),Cu~(2+),Cd~(2+) in simulated intestine condition could reach 418.7,686.6,849.5 μg / g,respectively.Besides,the pseudo- second- order kinetics equations were exactly fit for those adsorption processes of IDF for Pb~(2+)、Cu~(2+)、Cd~(2+).