Wood-decaying fungi, an important group in forest ecosystems, can utilize wood ma- trix for organism growth and play an important role in nutrient cycling in the forest ecosystems. In order to understand the community composition of wood-decaying fungi in temperate secondary forest ecosystems, four representative secondary forest ecosystems were selected in this study, e.g. Changbai Mountain secondary poplar-birch forest in Jilin Province, Baishilazi Nature Re- serve in Liaoning Province, Dongling Mountains Nature Reserve in Beijing, and Baotianman Na- ture Reserve in Henan Province. Based on field investigations and laboratory analysis, fungal flo- ra and diversity composition of wood-decaying fungi from the four sites were analyzed. In total, 73 wood-decaying fungal species were found in Changbai Mountain secondary poplar-birch forest, 104 species in Baishilazi Nature Reserve, 106 species in Dongling Mountain Nature Reserve and 124 species in Baotianman Nature Reserve. There were 18 common species among the four sites. Each site had its dominant fungal genera: Phellinus was in Changbai Mountain secondary poplar- birch with seven species, Trametes was in Baishilazi Nature Reserve with seven species, Hym- enochaete was in Dongling Mountain Nature Reserve with nine species and Polyporus was in Bao- tianman Nature Reserve with ten species. Comparison of the rarefaction curves of the fungi from the different sites showed that the dominant species of each site had positive relationship with their dominant hosts. And the composition of the tree species played a key role in the composition of the wood-decaying fungi. The genera geographical elements of polypores were dominated by cos- mopolitan element and the North Temperate element, with a distinct North Temperate character.