Solvent extraction of Au (III) in Cu-concentrate solution at PT Freeport Indonesia by using 8-Methylxanthine had been carried out. Three steps of research consisted of Synthesis of 8-Methylxanthine as an extractant, Selectivity and Ability Test of gold extraction, and its application for the sample of Cu-concentrate. The result of synthesis showed that the extractant 8-Methylxanthine was a yellowish white crystal with m.p. 366 – 368 0C. The selectivity of Au (III) extraction on to Cu as well as Fe metal ions was very high. The extractant 8-Methylxanthine was able to isolate Au(III) in the Cu-concentrate and the structure of compound obtained was predicted to be two nuclei complex compound.