Abstract: The specimens were collected by our expedition from the Neogene flora of Tengchong basin, i.e. 20 families, 29 genera and 35 species, four of which are described as new species, its show with characteristics as follows: 1. Tengehong basin flora developed from the Paleogene flora of Tethys sea and remains some eharaeters of the latter, for example, containing forest forms of Fagaeeae and Lauraeeae with evergreen boradleaves. Since Late Miocene the Himalayas uplifted, the Tecthys sea was recessive from the region, and this region had started aequiring its present day configuration. The climate became arid and cool. The flora was expanded with some deciduous elements. 2. The flora was expanded with Leguminosae elements which may indicate the climate changing to arid. The age of the flora is considered to Late Miocene- Early Plioeene. Its elements closely resemble with the modern ones of Yunnan flora.