Using the irradiation method, silver nanoparticles have been effectively synthesised into the zeolite framework (Agnano/Z). Firstly, silver ions have been introduced into the porous zeolite framework by ion-exchange reaction for creating Ag+/Z, then irradiated in ethanol solution by gamma Cobalt-60 for forming Agnano/Z. The conditions of the irradiation process such as: ratio of Ag+/Z to ethanol solution, irradiation dose...have been also investigated and chosen. The silver content in Agnano/Z has been determined by ICP-AES and characterized by ultraviolet- visible spectroscopy, powder X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM)... The antibacterial activity of the Agnano/Z has been investigated against Gram-negative bacteria Escherichia coli by both: quality and quantity tests. The results have shown that Agnano/Z possesses a high antibacterial property, namely the bactericide effect and can kill more than 98% of E.coli bacteria for shaking 0.5 g Agnano/Z in 100 ml of E. coli suspension containing about 106 CFU/ml. After mingling Agnano/Z with polypropylene plastic (PP) for the final silver content of about 100 mg/kg, PP/Agnano/Z has exhibited the ability to eliminate most of the bacteria on its surface. In conclusion, providing and maintaining the vigorously antimicrobial activity in Agnano/Z plastics is promising to be applied in antibacterial plastics.