Abstract: The subtropical rainforests of Castanopsis hystrax, Syzygium hancei Formation etc. discussed in this paper are located in the Hexi area (24˚56′N, 117˚14′E) of Nanjing County, Fujian Province on the north bound of the southern subtropical region in China.According to the survey of 12 plots totalling 1200m2 in the Liudao mountain of Hexi area, the floristic composition consists of 210 species of vasscular plants of 145 genera and 80 families. Analysis of the floristic geographical elements indicated that the percentage of tropical and pan-tropical elements (such as the species of Lauraceae, Myrtaceae, Rubiaceae and Myrsinaceae, etc.) is high, making up 80 % of the total genera.The Hexi subtropical rain forests consist of 7 associations in 3 formations, i. e. (1)Castanopsis hystrix, Syzygium hancei Formation (2) Castanopsis carlesii, C. hystrix Formation and ( 3 ) Syzygium hancei, Cryptocarya chinensis Formation.The evenness (J) and Shannon-Wiener′s index of species diversity (D) of the Hexi subtropical rain forests are 17.26% and 5.47 respectively. The analysis of age structure of the trees in the forests showed that the community is of relative stability, so the communities are one of zonal vegetation types of the southern subtropical region in China.