Abstract: Visible and electron spin resonance spectra of the copper (I) comple of partially quaternized poly(4-vinylpyridine) by ethyl bromide(EBQP₄VP) by ethyl bromide(EBQP₄VP) were measured. Effects of varying temperature, Iigand/Cu(J) mole ratio, pH value of solution and the percentage of quater-nization(Q) of polymer ligand on the coordination structure of polymer-Cu (I) complex were investigated. At ligand/Cu (Ⅱ) mole ratio 2011, the reduced viscosities of solution decrease with increasing pH value of solution or decreasing Q value. Hence the shape of the polymer chain is markedly crimple, the oxidation activity of catalytic hydroquinone increases. In this time the coordination of polymer-Cu(Ⅱ) complex[CuL₄] (L is polymer ligand) is a tetragonally distorted octahedral structure.