Abstract: Oceania was thought to be the distribution centre for Eucalyptus in the world. But the fossils of Eucalyptus were found in Xizang Autonomous Region and Sichuan Province of China recently. There is the recent flora composition in Jiangxi Province of China, which is similar to that in Xizang, Sichuan, Australia in geological ages. Based on plate Tectonics Hypothesis, Eucalyptus was originated from northern hemisphere and immigrated to the southern hemisphere through a long geological time which became their new distribution centre from then to today.