Abstract: Based on the floristic concept, the real meaning of tropical and subtropical Dian (Yunnan) -Qian (Guizhou) -Gui (Guangxi) are the Dian-qian-gui region under the Holarctic Kingdom and the Tongking Gulf region under the Paleotropic Kingdom. The former possesses ca. 6276 species in 1454 genera and 248 families, it is subtropic in nature but has strong features of the transition from temperate to tropical flora. The latter has ca. 4303 species in 1294 genera and 248 families and it is northern tropical edge in nature. According to the distributions of characteristic taxa and endemic taxa, the differences of vegetational zones and other azonal factors, these two regions can be classified into four floristical grade: kingdom, subkingdom, region, subregion. Dian-qian-gui region is divided in-to three subregions: South Guizhou-North Guangxi Subregion, Hon-shui river basin subregion. Southeast Yunnan subregion. Tongking Gulf region is divided into two subregions: Southwest Guangxi subregion, South Guangxi subregion. Three significant natural phenomena concerning above mentioned regions and subregions are discussed: 1. The Karst landforms widely develop, 2. they are paleoflora and are very complex in especial rich in tropical families, genera and species, 3. they are especially rich in endemic genera and species.

Key words: Flora