During the long term of interaction between plants and the abiotic stresses, and the biotic infestation, plants have evolved complex defensive mechanisms, for instance， plants emit herbivore-induced plant volatiles (HIPVs) so as to defend themselves against herbivores. HIPVs are the results of co-evolution in tritrophic interactions among plants, herbivores and natural enemies. The chemical compositions of the volatile compounds vary with both plant and herbivorous insect species. Within the various ecosystems, HIPVs play an important role in mediating interactions between plants and arthropods, plants and microorganisms, herbivore-damaging plants and undamaged neighboring plants, as well as damaged parts and undamaged parts of the same plant, and they mediate plants defensive responses. As host location signals，HIPVs play a critical role in attracting predatory and parasitical natural enemies. HIPVs may also act as chemical communication signals among plants, and trigger defensive responses against herbivores. From an ecological or economical point of view, the research and application of HIPVs are of great importance for development of integrated pest management strategy. Previous researches significantly enriched our understanding of insect chemical ecology related to herbivore-induced plant defense. However, a great deal of attention has recently been directed towards elucidating the molecular nature of induced plant resistance. In this review, we address following key issues related to the metabolic regulation mechanisms of HIPVs. First, we discuss the functionality of oral secretions of herbivores in the defense of plants, since plant damages are resulted from both herbivore mouthpart chawing (or piercing) and oral secretions. The synomone inducers Volicitin and β-glucosidase are components of oral secretions, and trigger the release of HIPVs, at least in part, by modulating the wound signals. Subsequently, we address the signal transduction pathways and their regulatory roles in the releases of HIPVs, and discuss- the interaction among various signaling pathways. As for metabolic process of HIPVs, it is regulated by signaling pathways, including jasmonic acid (JA), salicylic acid (SA), ethylene and H2O2. Among which, JA has long been suggested to be an important regulator of HIPVs. Based on the previous studies, we summarize the key metabolic processes of HIPVs and the regulation roles of key enzymes in the main transduction paths. HIPVs discussed in the current paper include terpenes, green leaf volatiles and aromatic compounds derived from shikimic acid pathway such as methyl salicylate (MeSA) and indole. As chemical signaling molecules, some compounds can also activate the expression of defense genes in neighboring plants. Terpene synthases are key enzymes involved in terpenoids production. Lipoxygenase and hydroperoxide lyase are the focuses in recent researches on the metabolic pathway of green leaf volatiles. Phenylalanine ammonia lyase and salicylic acid carboxyl methyltransferase are key enzymes involved in the formation of SA and its derivative MeSA, respectively. Whereas, the genes of these enzymes regulate the metabolic pathways of HIPVs at transcription level. Finally, we give a brief outlook of the future research and application of HIPVs.