Abstract: the complexation between glycine and Cu(Ⅱ) was studied by UV - Vis spectroscopy .The influences of complexation, such as temperature, ionic strength, coordination and pH value were observed. The result shows that: the ionic strength I = 0.1M;the complex rate of glycine and Cu(Ⅱ) (Gly / Cu) is 2:1; pH =7; The rate constant of the complexation was the largest separately, and the temperature will not affect the rate constant obviously. The complexation between glycine and Cu(Ⅱ) was second-order reaction, Activation energy was 7.009KJ/mol ,and free energy △G≠ was 4.321KJ/mol. The possible reaction mechanism for the complexation between glycine and Cu(Ⅱ) was proposed. The theoretical basis was provided for the preparation of high purity copper glycine.