Abstract: This paper researches the influence of different molecular weight polyvinylpyrrolidone on silver nanoconfiguration in polyol process. The silver nanoparticles are characterized by scanning electron microscopy and X-ray diffraction. Their optical properties are studied by UV-Vis spectrophotometer. The results indicate that under of silver nanoparticles different morphology will be made by different molecular weight polyvinylpyrrolidone under the same experimental conditions; the yield of silver nanowires is the largest when the molecular weight of polyvinylpyrrolidone is 1.0×104, and silver nanowires will reduce and silver nanocubes will increase when the molecular weight of polyvinylpyrrolidone increases.