Abstract: Identifying soil moisture transfer processes in permafrost influenced hillslopes is a key to understanding runoff generation processes in cold region. Isotope technology can obtain the information of hydrological process without destroying the original structure of soil. In this study, precipitation, groundwater, river water, and the soil water were collected during the thawing period of active layer (the thawing depth was about 100 cm) in a typical hillslope of permafrost watershed. The stable isotope characteristics of different water bodies was analyzed to explore the regularity of soil water migration in the source region of the Yangtze River (SRYR). The results indicated that, the variation of soil water δ18O was -14.58‰ ~ -1.58‰ (mean -8.25‰), the δD was -103.88‰ ~ -14.99‰ (mean -59.94‰). The isotopic component of soil water, river water and groundwater were all distributed near the local meteoric water line (LMWL), indicating that precipitation was the main source of these water bodies. The slope and intercept of evaporation lines were lower than that of LMWL, and the slope of groundwater evaporation line (GWEL) was the lowest, and it showed a heavy isotope enrichment, which indicated that the groundwater had experienced a certain degree of evaporation in the process of migration and transformation under the influence of evaporation and mixing effect. The complexity structure system of root layer made the soil water isotope show the most great variation and also had a heavy isotope enrichment phenomenon. The low d-excess value of the root layer indicated that it undergo a strong evaporative fractionation process. Except for river water, other water bodies had a greater temporal changes during the study period. Precipitation had little impact on soil water isotope compositions, while groundwater and soil water at 20~50 cm depth dominated the contribution of river water. This study has a positive significance for understanding the process of runoff generation and concentration in cold regions, and also provide basis for simulation and prediction of runoff process in cold region.