Abstract: Soil microbes play an important role in terrestrial carbon (C) and nitrogen (N) cycles via participating in litter decomposition and the turnover of soil organic matter. In this study, five subtropical forests along successional and altitudinal gradients were selected in Dinghushan Biosphere Reserve, China, including: (1) a pine forest (PF), a pine and broadleaved mixed forest (PBM) and a monsoon evergreen broadleaved forest (MEB) along a successional gradient; (2) a ravine evergreen broadleaved forest (REB), MEB (the same as along the successional gradient), and a mountainous evergreen broadleaved forest (MTEB) along an altitudinal gradient. In each forest, forest floor litters (separating into  undecomposed litter (L horizon) and a mixture of fragmented or humified litter (F/H horizon)) and underling mineral soils at 0-15 cm depth were selected in October, 2010. For each litter or mineral soil sample, microbial biomass carbon (MBC) and nitrogen (MBN) and the key associated edaphic properties (e.g. moisture content and the concentrations of total C, total N and total phosphorus (P)) were determined. Results showed that MBC, MBN, MBC/MBN ratio, total C, total N and total P all significantly decreased with the increasing extent of decomposition (L horizon →F/H horizon →mineral soil horizon). Both MBC and MBN in the F/H and mineral soil horizons significantly increased along the forest succession gradient (PF→PBM→MEB). MBC and MBN in the L horizon decreased in the order of PF>MEB>PBM. MBC and MBN of the L horizon but not of the F/H or mineral soil horizon significantly decreased with increasing altitude (RF→MEB→MTEB). Pearson correlation analysis showed that MBC was positively correlated with MBN in all horizons. Both MBC and MBN were positively correlated with moisture content in the L horizon, total P and dissolved organic N in the F/H horizon, and soil moisture content, total C, total N, and total P in the mineral soil horizon. Our results suggest that the relationships between soil microbial properties and edaphic properties depend on soil horizons, and are related to the different extents of organic matter decomposition, spatial location and nutrient availability of different soil horizons.