Abstract: Abstract Mt. Yunjushan is located at the northeast end of the Jiulingshan Mts. in north Jiangxi province, which has an ancient geological history. Since the Mesozoic period, it has kept in conditions of relative stablization and advantageous physiography. Its flora didn^t suf-fered danger by the glacier during the Quaternary. This paper studies on the origin and evolution of the flora in geological period. Based on statistics and analysis of families, genera and species in the present flora and comparison of re-lated regions, the flora features can be summarized as follows: 1) Mt. Yunjushan flora has the nature of the tropical consanguinity and the temperate de-rivation. The studies show that the tropical families are dominanting and the temperte species have the highest percentage (45.32). The flora may be origined chiefly from an ancient tropi-cal type during the Mesozoic and the Tertiary in ancient lands of S. China. Secondly, it may be derived from local elements and penetrated from N. temperate elements during the Quaternary. 2) The floristic origin is ancient, the flora is very rich in ancient and relic plants as well as in monotypic and oligotypic primitive types.

Key words: Mt.Yunjushan N.Jiangxi