In order to determine the impacts of different traditional forest management types on plant diversity of the seasonal tropical rainforests and infer effective conservation strategies, four types of forests with different management histories were studied in Nabanhe National Nature Reserve (NNNR), Xishuangbanna. China. They were: old-growth forest (non-timber product collection allowed), understorey planted old-growth forests, old secondary forests (similar to 200-years after slash and burn), and young secondary forest (15-50-years after slash and burn). Although human activities affected tree diversity and composition of the forests in NNNR, the forest regeneration potential of the different management systems were good. Even the young secondary forests, that showed the lowest Fisher's alpha diversity at the plot level, had similar diversity levels to old-growth forest when all plots were combined. Number of red list tree species, timber species, and edible plant species in young secondary forests was as high as those of old-growth forests, and higher than old secondary forests. Additionally, there were a number of vulnerable and endangered species that were more common in the secondary than old-growth forests, indicating the high conservation value of secondary forests. Understorey plantation in old-growth forest, however, impaired regeneration of the climax species. The beneficial effects of traditional forest use depend strongly on its small scale and its close proximity to undisturbed forest, which serves as a species source during secondary forest regeneration. Unfortunately, traditional forest use is now under serious threat by expanding large-scale monoculture rubber plantations