Abstract: Watersoluble matter (WSM) released during litter decomposition is an important source of carbon and nutrient in different forest aquatic and land habitats. Using litterbag method, leaf litter decomposition of four dominant species (i.e., Salix paraplesia, Rhododendron lapponicum, Sabina saltuaria, and Larix mastersiana) was examined in an alpine forest. We investigated the dynamics of WSM and water soluble carbon (WSC) contents and their related influencing factors during litter decomposition in stream, riparian zone, and forest floor at different periods (i.e., prefreezing period, freezing period, melting period, growing season, and late growing season). After two years of decomposition, we found that stream significantly promoted the release of WSM and WSC in leaf litter. The losses of WSM and WSC contents of the same litter species were significantly differed among different habitats (P<0.05), with stream>riparian zone>forest floor. The content of WSM decreased remarkably at the initial stage of decomposition. Across the whole decomposition process, changes in the contents of WSM (-70.43%) and WSC (-84.31%) showed a similar decreasing trend. In addition, the releases of WSM and WSC during leaf litter decomposition were significantly affected by decomposition period, litter species, and local environmental factors such as temperature, pH, and nutrient availability. These results suggested that WSM and WSC in decomposing leaf litter were easy to transfer to the downstream ecosystems with water flow. Environmental factors played an important role in the release of WSM and WSC during leaf litter decomposition, which provided useful information for our better understanding of material fluxes in alpine forests.