Using Copper nitrate trihydrate (Cu(NO3)2•3H2O) as precursor, hydrazine hydrate (N2H4•H2O) as reducing agent and Ploy(N-vinylpyrrolidone) (PVP) as capping agent in the presence of Diethylene glycol (DEG), highly monodisperse copper particles with different diameters were successfully synthesized via polyol method by different feeding strategies. Dynamic light scattering (DLS) and Scanning Electron Microscope (SEM) were used to characterize the morphology and particle size of these particles. X-ray diffraction (XRD) was used to measure the chemical constituents of these particles. UV-Vis spectrophotometer was used to signify the absorption spectrum of these particles. The results indicated that copper particles with controllable diameter can be synthesized by different injection rates. The average sizes of the prepared copper particles under 2, 4, 6, 8 ml/min of injection rate were 100nm, 200nm, 300nm, 400nm. The obtained copper particles were phase-pure crystalline, and their structure was face-centered cubic (fcc).