Abstract:Xanthium spinosum is an asteraceae plant from the South America,However,it was firstly found in Yining County,Xinjiang,China in 2009.This paper was investigated about 40 (cities) counties ranging from north to south of Xinjiang where X.spinosum probably occurred.We were also used the quadrate method to observe and analyze the abundance,frequentness and importance value of X.spinosum in the 23 well concentrated sample plots of different habitats;thus,the distribution areas and community characteristics of X.spinosum in Xinjiang were identified,and the optimum habitat of this species was also determined.Our results indicated that:(1)X.spinosum distributed in Changji City,Yining City,Yining County,Gongliu County,Tekes County,Xinyuan County,Chabuchar County,Huocheng County and Nileke County of Xinjiang at present.The altitude of its distribution areas ranged from 597~1 834 m.The types of its habitats included desert grassland and oasis.(2)In the two habitats,the relative abundances of X.spinosum was the most of all the plants,and the maximum value occurred in the oasis.Thus,X.spinosum was considered as the most important species in the invaded areas.Moreover,relative coverage of X.spinosum was the greatest in all the plants in its distribution areas,and the order of relative coverage of this species was the oasis (46.83%)>desert grassland(43.00%).(3)The analysis of important values of X.spinosum indicated that the comprehensive adaptability of this species was the highest in the two habitats,particularly in the oasis that it was invaded easily.In conclusion,the endangerment of X.spinosum was still in partial phase in desert grassland of Xinjiang,but this species almost spread in the oasis.Therefore,the relative departments should be attached it importance to prevent and control,do not let it continued to expand and spread.