Abstract: Three types of community of 5000 m2, herbaceous scrub, shrub forest and evergreen broad-leaved forest damaged by Mikania. micrantha, were established in the Country Park of Hong Kong. The herbicide sulfometuron-methy (concentration 0.05～0.1g#8226;m-2) was tested to kill M. micrantha. The effect of herbicide sulfometuron-methy killing M. micrantha and its influence on other plants and species diversity in communities were analyzed. The result was showed that sulfometuron-methy could kill M. micrantha effectively. 45 species of plants accounting for 30% of those in plots were affected in deferent degree by the herbicide after having sprayed the herbicide for 3 months. Liana and herbs were affected hardest by the herbicide, while shrubs and trees were affected slightly. After having been sprayed the herbicide for 14 months, shrubs and trees with spotted and dead leaves grow normally, and withered herbs have renewed. The species diversity of the communities has increased gradually after M. micrantha were killed by the herbicide.