Abstract. Efficient full use of fly ash is still an important issue which has been troubled by the developing countries like China, and a large area subsidence as a result of coal mining also give rise to serious damage for agricultural soils. The agricultural soil profile reconstruction is great significance with fly ash as a substrate because of combining the two problems. In this paper, the feasibility of soil reconstruction is discussed through studying the physio-chemical properties and hydraulic characteristics of fly ash. The results show that the physio-chemical properties of fly ash layer in reconstruction soil profile tend to healthy development with rehabilitation time increasing. Though fly ash layer has a higher water content and poor ability of water vertical upward movement compared to surface soil, but the parameters values are basically appropriate to crop production and not evidently decreasing yields. As for potential groundwater pollution due to solute downward transport of reconstruction soil, we will start further research and draw up solution.