Abstract: The processes of water diffusion in non-saturated soils and the relationship between water diffusion rates and water contents were simulated by horizontal soil columns from saline-alkalined wetland in Xianghai National Natural Reserve. The results showed that water diffusion rates of saline-alkaline soils were lower. water diffusion rate in the layer of 10～20　cm was lower than that in other layers; they were higher for water diffusion rates in bottom layers than those in upper ones; and water diffusion rates increased by exponential with the increase of water content, moreover, the increase curves of top soils were steeper.

Key words: saline-alkalined wetlands, horizontal soil column, non-saturated soils, water diffusion rates