Monodispersed and nano-sized Cu powders were synthesized from copper sulfate pentahydrate (CuSO4ㆍ5H2O) inside a nonionic polymer matrix by using wet chemical reduction process. The sucrose was used as a nonionic polymer network source. The influences of a nonionic polymer matrix on the particle size of the prepared Cu powders were characterized by means of Xray diffraction (XRD), scanning electron microscopy (SEM), and particle size analysis (PSA). The smallen Cu powders with size of approximately 100㎚ was obtained with adding of 0.04M sucrose at reaction temperature of 60°C. The particle size of the Cu powders prepared by the reduction inside polymer network was strongly dependent of the sucrose content and reaction temperature.