Abstract: Foreign invasion plant flase ragweed (Iva xanthifolia)is spreading rapidly in the Northeast of China, which threatens the natural ecosystem and does harm to people’s health. By doing field work distribution of flase ragweed in Northeast China was detected. Maxent ecological niche models help to predict the potential suitable regions of flase ragweed both in China and the other parts of the world. And natural intermittent points classification method of ArcGIS helps to classify the risk regions. The receiver operating characteristic curve was applied to access the prediction accuracy. The main environmental variables were analyzed by Jackknife approach and response curve of environmental variables. The results showed that flase ragweed had a wildly suitable regions which continue to spread its areas. In China, the suitable distribution area mainly locates in the North, the Northeast, the East, the Central, the Southwest and the Northwest of China; most of the suitable regions were in Heilongjiang, Jilin, Liaoning, Shanxi, Shanxi, Henan, Hebei, Shandong, Beijing, Tianjin, Neimenggu and Xinjiang. In the world, risk regions existed worldwide except Antarctica; the risk regions mainly lie in North America (including Canada and America), Africa (Morocoo), Europe (Spain, Croatia, Hungary, Slovakia, Bosnia-herzegovina, Serbia, Macedonia, Bulgaria, Georgia, Armenia and Azerbaijan), and Asia (Turkey, Iran, Kazakhstan, Tajikistan, China, North Korea, South Korea and Japan). The above areas show that middle latitude regions with higher average annual temperature, the lowest in the coldest month or lower average temperature in coldest quarter are the most suitable for flase ragweed to grow.