In this paper, a brief account on the soil forming conditions and the rule of soil distribution in the plain of Xinjiang is given. The position, the index and the name of plain soils to be classified are compared between Chinese soil genetic classification and Chinese soil taxonomy. The aridic epipedon appeared in the soil taxonomy system and the differentiation between the steppe desert soils and the desert soils are discussed. The purpose of this paper is to provide the reference for soil classification in Xinjiang.