Located in the south rim of the mid-subtropical area in East China, Mount Jinggangshan region in Jiangxi Province is a humid area of the northern hemisphere. With its location in the middle of Luoxiao Mountains, it has towering topography, deep valleys, extremely diverse habitats, and conserves typical monsoon forests in its valleys. We selected six typical ravine monsoon forest communities, aiming to investigate the characteristics of the communities' synecology and biogeography. The results show that: (1) The community composition is characterized by rich and typical tropical family, such as the Lauraceae, Fagceae, Theaceae, Rubiaceae, Hamamelidaceae, etc.; tropical-subtropical element is dominant in the geographic component of seed plants, accounting for 64.71%-77.94% of the total genera, which is higher than in other mountains of the same latitude, close to or even higher than the monsoon broad-leaved evergreen forests in south sub-tropical zone. (2) The community structure has poly-dominant species and typical key-stone species, and is much different from the subtropical evergreen broad-leaved forests which is often mono-dominant or few species dominant in structure. (3) Shannon-Wiener index for the species diversity is 4.44-5.46, the species are quite rich, showing obvious tropical vegetation features in south subtropical zone. (4) The ravine monsoon forests in Mount Jinggangshan region are indicative of obvious characteristics of tropical rain forests in ecological habit, such as typical large woody climber, buttress root, garroting phenomenon, draining point, rich parasitic plants and epiphytes, orchids and tree ferns. There is no doubt that monsoon forest communities in subtropical valleys of Mount Jinggangshan region has distinguishing characteristics of transition from tropical rain forests to the subtropical evergreen broad-leaved forests, which is often known as intrusion communities in terms of succession, or super zonal plant communities formed through long-term evolution.