A simple ATPS of polyethylene glycol/sulphate salt was proposed for the extraction of Cu(II) ions from aqueous media. Maximum extraction efficiency of Cu ions was obtained in the aqueous PEG2000/ sodium sulphate two-phase system. In the following, design of experimental methodology using Taguchi orthogonal array was applied to evaluate the effects of four independent variables on the partitioning behavior of Cu ions from aqueous media. The results indicated that the temperature and pH of the system were the major contributory factors for Cu ions partitioning. The maximum extraction efficiency of Cu ions was determined to be 77.89% under the optimal conditions.