Abstract: The entire irrigation district is divided into three terraces based on the geology and geomorphology about Luohui Trench in this research, watersalt in soil dynamic behavior? on the three terraces is realtime monitored on the spot, and the paper detailedly analyzes the change situation of groundwater conductivity along with groundwater depth at different stages and in different distributed conditions using the method of double factor variance analysis. The results indicate that groundwater conductivity has close relation with water level, and this situation exhibits strong regional characteristics that the increase of EC value on each terrace is along with the rising of the water level, the high ?EC value always appears in the high water level district, and there exists significant variation of conductivity on the first terrace. In addition, the outside factors such as the microregion environment, the human activity, the climate etc., also can affect the dynamical process of groundwater and salt. Therefore, the reduction of the water level in this irrigation district is an important measure to control the soil salinification and it is a key to realize the agricultural sustainable development.

Key words: groundwater salt , dynamic law, groundwater level , groundwater conductivity , spatial variability