Abstract: Objective To synthesize a new kind of anodic charge materials-alaminum-magnesium hydroxide and to design an enrichment method to concentrate bacteria from water environment.Methods Anodic chargematerialsalum inium-magnesium hydroxide was synthesized by chemosynthesis and grinded to particle for a filter.The particle size,surface condition of the filter and composition of the filter were investigated with scanning electron microscope and energy spectrum technique.A filtration device to absorb and concentrate the bacteria in water was made with the anodic chargematerial.The method of enriching bacteria from water was established.Results The filtering material is mixed metal dual hydroxides and the prop ortion of magenesium and a luminiam is 2.41:1.The size of the filter particle is about 250μm in diameter and uniform.The estab lished method with the filter materidal could filter out 95% of bacteria from tap water.The enrichmetn system established could treat 15 liters of water.Conclusion With the anodic chargemate rial,the enrichment method could perfectly concentrate bacteria in water samples.