Abstract:Shishan is part of the Kam-Yunnania (Sikang-Yunnan ancient landmass) , which has an ancient geological history. After the Tertiary, it keeps relatively stable and has advantageous physiography conditions, its flora did not suffer severe danger by the glacier during the Quaternary.The study area is located in the southern portion of the middle subtropical region, it covers an area of ca. 100 km2 and reaches 2419.8 m in altitude. Its general climate is similar to that of Kunming, with only two seasons: dry and wet. The annual average temperate and rainfall are respectively 15.1 °C and 1004 mm, the solar radiation energy is up to 127 Kcal./cm2 annually. Floristically, it is situated in C Yunnan subregion, Yunnan plateau region belonging to Sino-Himalayan forest subkingdom of Holarctic kingdom. Due to the location of the transition of the mountain and it is a relatively undisturbed area in C Yunnan, the investigation on the Shishan mountain vegetation and flora is helpful for us to understand the phytogeographical significance of this area and its adjacent regions.