Abstract:The effects of soil water availability and the days after budbreak on the root hydraulic conductivity in Haloxylon ammodendron sapling with potted plants was quantitatively analyzed. The results showed that the entire root hydraulic conductivity of Haloxylon ammodendron sapling increased linearly with soil water availability and the days after budbreak; the root hydraulic conductivity per unit root surface area of Haloxylon ammodendron sapling increased at first and then decreased according to parabola with soil water availability, and the root hydraulic conductivity per unit root surface area of Haloxylon ammodendron sapling decreased linearly with the days after budbreak. The obtained quantitative relationships between root hydraulic conductivity of Haloxylon ammodendron sapling and soil water availability and the days after budbreak can be applied to the research of root water uptake dynamic models and the research of plant water transfer.