Abstract: Soil classification is the basis for understanding the soil,and a basic method for soil research.With the development of soil science,soil classification is constantly advancing.In this paper,author described the gradual development process of soil classification from international to domestic and the past to modern times,elaborated that soil classification experienced a qualitative classification era that represented by the genetic soil classification in early times,soil classification came into a quantitative classification era that represented by the soil taxonomy,starting a new milestone.Especially,the recent research on soil series,primary taxon of the soil taxonomy,has become a hot spot research in soil classification,also is an important method and means of soil classification study,which has important significance for soil geography study.