Abstract: The behaviour of oxygen in melting copper in the refining process of anodic copper was studied by thermodynamic analysis. The level of impurity and the extent of oxygen in melting copper which must be controlled at end-point of oxidation and reduction were also evaluated by thermodynamics. A high temperature oxygen sensor was used to track the change of oxygen and to direct the refining operation during the test of refining anodic copper. The result of experiment, a smooth surface and high physical quality anodic plate was successfully got from raw copper containing high nickel and sulphur.