Seedling, made up of small individuals of woody plant species in the understorey, is an important component of many forests and considered as an important source for natural restoration in forest ecosystems. Simultaneously seedling plays an important role in the regeneration of numerous tree species. Based on space-for-time substitution method, we treated coniferous and broad-leaved mixed forest, secondary monsoon evergreen broad-leaved forest (MEBF), primary MEBF in the same area as three different stages of secondary succession of MEBF. Eight sampling plots representing the three different stages distribute in Caiyanghe nature reserve, surrounding the areas of Meizihu and Xinfang reservoir of Puer, in Yunnan Province, the southwest of China. We investigated seedling regeneration characteristics of woody plants of MEBF during secondary succession by looking at species composition, density, height level and the relationship with environmental factors. Overall, we found 2014 individuals of woody seedlings belonging to 101 species (dominated by understory tree species) in the eight plots covering 144-m² area. The species richness of tree seedling, shrub seedling and liana seedling were 50, 29 and 22 respectively, and their corresponding individuals were 1499, 299 and 216. Tree seedling was the main component of woody plant seedling, such as Castanopsis echidnocarpa. Pinus kesiya var. langbianensis are dominant species in coniferous and broad-leaved mixed forest, however, their seedlings rarely appeared in the understory. The pine seedling stages need more light than shade-tolerant species which can conserve seedling bank in understory and waited for appropriate chance to regeneration. The woody plant seedling density of coniferous and broad-leaved mixed forest, secondary and mature MEBF was 183±5.69, 240±20.31 and 372.5±4.5 individuals per 18m². As succession progresses, the density of total woody seedlings, tree seedlings and liana seedlings all increased, while the density of shrub seedlings did not change significantly. Celastrus virens as a liana was particularly conspicuous in mature MEBF. Species richness of liana seedlings tended to increase, while species richness of tree seedlings and shrub seedlings remained relatively stable along the succession gradient. The Shannon-Wiener index of woody seedlings was significantly lower in primary MEBF than those in mixed forest and secondary MEBF. The abundance of woody seedlings in secondary and primary MEBF decreased with the increase of height level, while in mixed forest, the abundance of woody seedlings form a unimodal pattern with peak at 20 cm. Species richness, however, showed consistent (increasing or decreasing) pattern with the increase of height level in all these forest types. Distribution of woody seedlings abundance concentrated in 0-20 cm in the three community types. Woody seedlings species richness of mature MEBF was significantly lower than coniferous and broad-leaved mixed forest when height level was at Ⅰand Ⅱ. Sørensen index indicated a close link between tree and liana seedlings and the species composition of the community. Moreover, tree seedling density distribution was significantly negatively correlated with the slope of the plot, while shrub seedling density was significantly positively related to soil pH.