Abstract: The effects of biological invasion on the biodiversity,health of human being,land,soil,rivers and lakes,energy balance of urban ecosystem are stated in this paper.Setting up the database of biological invasion,perfecting the law and rule,realizing the lawful management,increasing the ability of inspection on the border,developing the study of ecological evaluation,spreading the propaganda of ecology knowledge are the valid strategies of preventing biological invasion.Manual or mechanical, chemical and biological controls, allelopathy are suggested methods of curing biological invasion.