Soil extracellular enzymes participate in soil biochemical processes. Their activities and stoichiometry can reflect the functional dynamics of soil microorganisms. However, the variations and the determining factors of the activities and stoichiometry of soil extracellular enzymes that catalyze different biogeochemical processes in wetland ecosystems along the elevation gradient are still unclear. Therefore, in the current study, we measured the activities of seven soil hydrolytic enzymes which related to carbon, nitrogen, and phosphorus cycling using the surface soil samples (0-10 cm) of a typical Carex lakeshore at Lake Poyang wetland, China. The results showed that the α-glucosidase (AG) activity gradually decreased with the increase of elevation, but the β-xylosidase (XYL) activity showed the opposite trends. Along the elevation gradient, β-glucosidase (BG) activity did not significantly change; while the cellobiohydrolase (CBH) activity first decreased and then increased. With the increase in elevation, the activities of β-N-acetylglucosaminidase (NAG) and leucine aminopeptidase (LAP) gradually decreased; whereas the phosphatase (PHOS) activity had no significant variation. Along the elevation gradient, BG:NAG ratio gradually increased, AG:PHOS ratio gradually decreased, while NAG:PHOS ratio had no significant change. The structural equation model (SEM) analyses showed that the most important determining factors of soil extracellular enzyme activities were elevation, plant species richness and soil total P. BG:NAG ratio was mainly affected by elevation, and AG:PHOS ratio and NAG:PHOS ratio were mainly impacted by soil pHs.