Abstract: Based on the soil water content and stable isotopes in 0-130 cm soil depth, groundwater and precipitation in a Cinnamomum camphora grove in Changsha from March 2017 to February 2018, the characteristics of stable isotopes in soil water and the relationship between isotopic composition of soil water and precipitation were analyzed in order to reveal the movement of soil water in this area. The results showed that:(1) The seasonal variations of soil water content during the observation could be divided into three stages, i.e. water-rich period from March to June when soil water storage was large and kept stable, water consumption period from July to October and water replenishment period from November to following February. Soil water content increased from surface to deep soil, and its stability increased. The soil water content showed a larger vertical difference in water-consuming period than that in water-replenishing period and than that in water-rich period. (2) The daily effective precipitation P at the survey site was larger than 3.3 mm due to canopy interception and surface litter absorption. The slope and intercept of LMWL_{P > 3.3 mm}(local meteoric water line under P > 3.3 mm), very close to SWL (soil water lines) at different depths, were significantly higher than those of LMWL. (3) From surface to deep soil, the influences of water infiltration, mixing of old and new soil water and soil evaporation on the stable isotopes in soil water gradually decreased. The average δ¹⁸O in 0-40 cm soil water showed greater values in water-rich period than that in water-replenishing period and than that in water-consuming period, but insignificant seasonality in 40-130 cm soil water. (4) The average lc-excess (δD deviations from the LMWL) in different water bodies during the observation period showed higher value in precipitation (0) than that in groundwater (-2.80‰) and than that in soil water (-5.00‰). The lc-excess in soil water increased with depth. Because the mixing of old and new water was a continuous and cumulative process, and was impacted by different soil structures, soil textures and precipitation events, there appeared significant time delays with soil depth in supply of soil water.