Abstract:Volatile organic compounds（VOCs） act as a media for plants to communicate and interact with the environment. Plant VOCs play a vital role for plants in attracting pollinators, promoting the dispersal of seeds, and having allopathic effect against germination of other species. In recent years, Plant VOCs as signals have been shown to play an important role in the ecosystem function, and have increasingly received more attention. The present paper reviewed advances in plant defense mediated by the signal function of plant VOCs. In some cases plant VOCs can have a direct defense mechanisms against herbivory. It is believed that VOCs can transfer within plant and between the plants of the same species and different species to improve the defense mechanisms of the respective plants, indicating their crucial role in ecosystem function. Finally，we discussed the research method and the potential ecological functions of plant VOCs.