Abstract: This paper deals with the virgin Taiwania flousiana forest in northwest Yunnan. By studying its growth and developing conditions, distributions, floristic elements, community structure and auto-developmental process, we come to the conclusion that this forest, which is a rare and greatly valued relic community existing in north-west Yunnan at present, is about 300—500 years old, although a few of the trees may be more than 1000 years old.