Invasive alien species colonize the environment and are aggressively a mediator of change and threaten native biodiversity of Pakistan. Invasive species are the species that has been accidentally or intentionally introduced to a different habitat which may be any species, including its seeds, eggs, spores, or other biological material capable of propagating that species, that is not native to that ecosystem. The introduction of these species likely to cause economic or environmental harm or harm to human health. One day consultative workshop was held at NARC, Islamabad in Pakistan on 17 September 1999, to identify, evaluate, and rank non-native plants that threaten the ecological integrity of wildlands and cropping systems. The focus was on species that are already established in areas that support native ecosystems, such as parks, reserves, wildlife areas, national forests, and rangelands.  Fourteen plant species have been identified through a one-day consultative workshop on Alien Invasive Species.  These plant species include trees and shrubs mainly as well as aquatic plant species.  Key words:- species ,plants , invasive , plant , alien , pollen