A new electron beam method has been successfully developed to prepare silver nano-particles at room temperature and ambient pressure, without any kind of catalysts. The structure, morphology, size, optical properties and the melting point have been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible spectrophotometer (UV-vis) and differential scanning calorimeter (DSC) were utilized to characterize the product. TEM results show that the average size of silver nano-particles is about 30nm in agreement with the calculated value size from XRD using Scherer formula.