Abstract: Influence of three volatiles from tropical rank grass on behavior of Plutella xylostella was studied in the test of olfactory response. Three volatiles of tropical rank grasses showed a good deterrent effect on the adult of the diamondback month (DBM), and that the deterrent effects strengthened with the flow rate of volatiles enhancing. There was better deterrent effects on adults of DBM for the volatiles from Artemisia argyi and Piper betle than that from Eupatorium odoratum . In the test of oviposition deterrent and antifeedant of DBM, these volatiles extraeted from tropical rank grasses showed a inhibitory effects. The order of oviposition deterrent and antifeedant of DBM effected by the volatiles is: Piper betle> Eupatorium odoratum> Artemisia argyi.