Abstract: Many exotic plants were able to restrain native plants, animals and microbes in a new habitat by releasing allelochemicals.More and more studies showed that the allelopathy of exotic plants played an important role in their successful ecesis.The allelopathy of exotic plants and releasing approach and acting mode of the allelochemicals were reviewed, and the acting mechanism and influencing factor of exotic plants allelopathy were discussed.The existing problems and direction in the study on exotic plants allelopathy were advanced in the end.