Phenols are important secondary metabolites in plant tissues, and provide well protection against the attacks by pathogenic microbes. Arbuscular mycorrhizal (AM) fungi can induce the biosynthesis of phenols in plants both locally and systematically. Recently, research has been intensively reported on this aspect. In this paper, the localized and systematic induction of phenols by AM fungi is reviewed. The possible signaling molecules (SA, H2O2) in the induction process are put forward, and the putative action model involved in the biosynthesis of phenols induced by AM fungi is further presented. Some research perspectives for the future are also pointed out.