Abstract:This paper analyzes the influence of the river flooding disturbance on biodiversity of the degraded ecosystem and discusses the function of the disturbance on the vegetative restoration in the lower reaches of Tarim River. The results show: (1) there are seventeen species, thirteen genera and nine families before river flooding in the lower reaches of Tarim River while thirty-four species, twenty-six genera and twelve families after river flooding , in which appear eighteen new species; (2) from the plants diversity indices in investigated samples, the species diversity and riches indices in river flooding areas increase more obviously than those in non-flooding areas;(3) from the importance value of the different species after one time of river flooding, the annual herb grow quickly while the perennial herb with deeper root or root clone becomes a dominance in plant community; (4) after several times of river flooding, some arbors and shrubs such as Populus euphratica and Tamarix ramosissima Ledeb are prone to germinate and become a ecologic dominance in plant community; (5) during the period of river flooding, the ecological characteristics of the overground vegetation have differences due to the different intensity of the river flooding disturbances caused by microtopographty; (6) the discussed results indicate that the river flooding disturbance has an obviously favorable influence on restoring the degraded ecosystem in the lower reaches of Tarim River. The influence is connected with the integrality of restoring the ecohydrological process.