Polyacrylamide (PAA)-metal nanocomposites were successfully synthesized without blending, at room temperature as follows: a water-absorbent material was used to absorb metal solution (Ag + , Cu + ) and then irradiated in the 6 0 Co γ-ray field. The network of the hydrogel prevented the aggregation of silver particles. The products were dried and characterized by X-ray diffiaction (XRD) and transmission electron miscroscopy (TEM). The mechanism of ion reduction is discussed.