This paper briefly introduces the nature conditions, salinization and current amelioration situation of alkalized soils in the Hetao irrigation district, Nei Mongol. Formation, properties and characteristics of the alkalized soil in the district are revealed in the paper Formation of alkalized soils in the district are summarized as follows: 1. Most of the seriously alkalized soils in the district were formed due to large quantity of residual sodium carbonate and intense evaporation of ground water under arid climatic conditions, being characterized by high degree of alkalization of whole soil profile. 2. Sodium ions contained in ground and surface water were concentrated by absorbing complexs in the soils under the influences of various factors. The soil surface are commonly found with a high degree of alkalization. 3. Some low-lying land soils were alkalized as a result of biological actions.