Abstract: For effectively killing the bacillus coli in the water and adsorbing endotoxin released on the death at the same time, the new bi-functional material of Ag nanoclusters enclosed into X-zeolite (Ag@NaX) was prepared by in-situ synthesis method for the first time. The results of HR-TEM and STEM show that most of the Ag clusters are uniformly located at the zeolite cages, whose average size is 1.03 nm. This bi-functional material was used for killing the bacillus coli in water and showed an excellent performance. The amount of 2.5 mg/100 mL material (1.07wt% mass fraction of Ag loading) could totally remove the bacillus coli at 20 min. The endotoxin released on the death is also adsorbed by the zeolite efficiently, leading to the amount of endotoxin keeping at 8×10⁻⁹g/100 mL, whose amount is lower than the safety standards of endotoxin for drinking water in relevant regulations. The composite material has excellent bi-function of sterilization and adsorption at the same time under the join effects of Ag clusters and zeolite endow. The material has a excellent stability due to the Ag clusters is effectively prevented from losing by the zeolite skeleton, which leads to the performance of this material keeping well after several numbers of using.