Yunnan, an inland province at a low latitude and high elevation, lying between 21°09\\\–29°15\\\N and 97°32\\\–106°12\\\E in southwestern China, has a vast territory with diversified and unique nature resources. There are more than 18 000 high plant species (51.6% of China\\\s total) and 1836 vertebrate species (54.8% of China\\\s total) living in Yunnan on a land area of 394000km2, i.e., only 4.1% of China\\\s total. Among 15000 seed plants found in Yunnan there are 151 rare and endangered plant species (42.6% of China\\\s protected plants). Out of 335 China priority protected wild animals, Yunnan has 243 species, accounting for 72.5% of China\\\s total, 15% of which are species endemic to Yunnan. However, Yunnan\\\s biodiversity is faced with the menace of excessive exploitation of resources and changes in environmental conditions caused by the activities of an expanding human population. This paper discusses the background, the composition, and the structure of Yunnan\\\s biodiversity. Its biodiversity fragility and the threatened situation are also discussed. Suggestions and recommendations on the strategy and actions of Yunnan biodiversity conservation and sustainable development are proposed.