Abstract:Eucalyptus is well-known as an effective reforestation tree species, due to its fast growth and high adaptability to various environments. Howev er, the introduction of Eucalyptus could have negative effects on the local envi ronment, e.g., inducing soil degradation, decline of groundwater level, and decr ease of biodiversity, and especially, there still have controversies on the effe cts of introduced Eucalyptus on the understory biodiversity of indigenous pl ant communities and related mechanisms. Based on a detailed analysis of the literatu res at home and abroad, it was considered that the indigenous plant species in t he majority of introduced Eucalyptus plantations were lesser than those in n atural forests and indigenous species plantations but more than those in other exoti c species plantations, mainly due to the unique eco-physiological characteristi cs of Eucalyptus and the irrational plantation design and harvesting techniq ues, among which, anthropogenic factors played leading roles. Be that as it may, the negative effects of introducing Eucalyptus on local plant biodiversity coul d be minimized via more rigorous scientific plantation design and management based o n local plant community characteristics. To mitigate the negative effects of Eucalyptus introduction, the native trees and understory vegetation in plantations should be kept intact during reforestation with Eucalyptus to favor the normal d evelopment of plant community and regeneration. At the same time, human disturba nce should be minimized to facilitate the natural regeneration of native species.