The Qinling-Daba Mountains (QDM), extending east-west in central China, span warm temperate and subtropical zones and are characterized by complex geographical transitions and high biodiversity. They actually also act as a significant ecological corridor between the Tibetan Plateau and East China plains, but this almost has not been addressed. This study uses plant species data of 40 national nature reserves within QDM and 18 in adjacent area, performs consensus clustering at the levels of species, genus, and areal-type, traces the origins and dispersal routes of 89 Chinese endemic genera, and, finally, assesses the importance and areal differentiation of environmental factors on species distribution. The results show:①The QDM as a corridor contribute greatly to the high biodiversity in the study areas, particularly in the easternmost and westernmost sections,②The QDM promote species interactions and exchanges between west China and east China. Central-East China components (41 genera) and North China components (8 genera) spread southwestward; Southwest components (24 genera) spread eastward and northeastward; while Northwest components (6 genera) show limited eastward spread. ③Multi-year average precipitation, elevation, and coldest quarter temperature significantly influence plant distribution.④Elevation differences (peak, base, and average) under 1000m among reserves enhance plant dispersal, resulting in obvious corridor effect. This study provides theoretical support for understanding the corridor effect in the study area and its contribution to biodiversity pattern of China.