Abstract: Soil water retention curve is an essential input parameter of soil water and solute transport model. According to the conventional van Genuchten model and Campbell model， an improved model of soil water retention curve was presented based on adaptive weight. The case study showed that the improved model was more adaptable， and could yield better simulation results. In particular， the improved model as a continuously differentiable function can satisfy the premise of the numerical solution of the Richards equation. So， the improved model was of great application potential.

Key words: soil water retention curve （SWRC）, soil texture, model, adaptive weight