Abstract: 1. There are 56 families of flora commonly distributed in Zhejiang, Taiwan Provinces of China and Japan. There are 71 families, 148 genera 222 species similar in Zhejiang and Japan, and 68 families, 135 genera, 214 species similar in Zhejiang and Taiwan Provinces. It denotes that the relationship of Zhejiang and Japan is closer than the relationship of Zhejiang and Taiwan.2. All kinds of elements of the tropical forest flora are common in Zhejiang, Taiwan and Japan. The common tropical elements in Zhejiang and Japan are 68 genera, i. e.46 percent of the total common genera. There are 82 common genera of tropical elements in Zhejiang and Taiwan, i. e.61 percent of the total common genera. It denotes that the relation of tropic elements of the later is more closer. than the former.3. The East Asian elements in Zhejiang and Japan arc onefold more than Zhejiang and Taiwans'. All kinds of the temperate elements, and the cosmopolitan genera in Zhejiang and Japan are much more than in Zhejiang and Taiwans'. For example, Rosaceae is common and much more in Zhejiang and Japan. It has 13 genera, 23 species, seven genera of them are the temperate (the North temperate one, the old world temperate one), four genera of them are the East Asian, one genus of them is the consmopolitan and the East Asian and the North American have one genus respectively. There are only two genera, four species of woody plants of Rosaceae in Zhejiangand Taiwan. They are all the North temperate elements.4. The endemic elements only exist in common flora of Zhejiang and Taiwan. There are no endemic common flora in Zhejiang and Japan. It shows that the division between Taiwan and the Continent happened at a later stage and the Continent has great influence on Taiwan.