Anti-aging agents for rubber are widely acknowledged as an auxiliary material indispensable for protecting rubber from internal and external deterioration factors, achieving required performance and extending product life. The phenolic antioxidant is used as a primary antioxidant together with the amine antioxidant, and it is particularly used for a rubber product which dislikes coloring, discoloration and migration stain. In addition, the phenolic antioxidant has been increasing in type and application with the development of resins and oils. It is difficult to be classified with a chemical structure. In the first half of this article, we will pick up some of phenolic antioxidants and explain the structure and function. And, in the second half of the article, we would like to report on the results from the compounding technique, mainly on heat resistance and discoloration, about the effect actually used for rubber.