The dynamics of chemical types and main components in vertical profile of soil and groundwater in salt-affected soil area are focused in this paper.The results from the typical sites of soil-groundwater during 4 years show that most of the dynamics classes for soil chemical types in this area are seasonal variation class,the next is relative steady class.For the chemical types of groundwater,most of the dynamics classes are relative steady class,the next is transform class and no seasonal variation class.The dynamics of chemical types for groundwater is steadier than that for soil and the chemical type of groundwater is not always coincident with that of soil at same site.The dynamics of the vertical variations for main component in the soil-groundwater reflects the influences of landform,climate,man-made measures and the migration law of geochemical components. The principles of the classification for the dynamics of chemical types of salt-affected soil and groundwater,the simplified indexes for determining the main components and the unity of the indexes and nomenclature of chemical classification for the salt- affected soils and groundwater with other disciplines are put forward in this paper.