Abstract: The feeding of herbivores induces plant to release special blends of volatilesguiding natural enemies to herbivores. This can prevent plant from severe damage, and is called "plant indirect defence". Since its discovery by Marcel Dicke in 1988, the research on herbivore-induced volatiles (HIV) has been paid with great attentions all over the world, and a good number of investigations have been reported. According to them, this paper summarizes that: (1)HIV is induced by herbivores feeding on plant and different from green leave odour, (2) HIV is emitted systematically several hours after herbivores begin injuring, displaying diurnal rhythm similar to the natural enemies' foraging behaviour, (3)HIV generally contains several kinds of terpenoids, (4)specificity of HIV is much lower when different herbivores damage the same plant than when the volatiles are released by plant of different species and cultivars. Additionally the function and induction mechanism of HIV are fully discussed.