Abstract: Four typical wetlands in the Honghe Wetland Reserve of Sanjiang Plain (i.e. wetlands with the following dominant plant species: Calamagrostis angustifolia+Salix brachypoda, Calamagrostis angustifolia, Carex lasiocarpa, and Phragmites australis) were selected to analyze the changes of soil organic carbon (SOC) and total nitrogen (TN) contents and various indices of microbial characteristics including soil sucrose, catalase, cellulase, microbial biomass carbon/nitrogen (MBC/MBN), microbial respiration (MBR), microbial quotient (q_MB), and metabolic quotient (qCO₂), as well as the correlations among them. The results showed that SOC and TN contents decreased with increasing the soil depth, and varied significantly (P<0.01) in the different wetland types. Soil enzyme activities (except catalase), MBC, MBN and MBR also decreased significantly with increasing the soil depth in the wetlands with the greatest activities being detected in surface soil (0-10 cm). In soil layer of 0-30 cm, several parameters (including SOC, TN, soil enzyme activities, MBC, MBN, MBR, q_MB and qCO₂) were higher in the wetlands dominated by C. angustifolia+S. brachypoda and C. angustifolia, compared with those with C. lasiocarpa and P. australis as dominant plant species. Statistical analyses revealed significant correlations (P<0.01) between major microbial indicators (except qCO₂) with SOC and TN contents in the soils. It demonstrated that the microbial characteristics were the major indicators, and played an important role in the changes of SOC and TN in wetland soils.