The invasions of exotic plants and their effects of ecosystems were reviewed and analyzed.There are many factors which can effect plant invasions.Some of them can promote invasions of plants,while other factors can inhibit invasions.All factors can be divided into internal factors and external ones.The effects of exotic species to ecosystems are mainly on the productivity,soil,water,disturbance,community structure and dynamics.We should research the characters and effect factors of exotic plants,then integr...