Study on numerical classification for 34 soil profiles in Chenggian County of Gansu Province was carried out by means of a cluster analysis method of standardized variateoblique distance-sum of square error. Indexes used in numerical classification include soil pH, organic matter (O. M.),total N, totoal P, total K, available P, available R, cation exchange capacity(CEC) SiO₂, Al₂O₃, Fe₂O₃, CaCO₃ and physical clay(<0.01 mm). Ii,esults obtained from this study showed that 34 soil profiles used in the egperi.ment may be divided into five soil groups. From variance analysis for eight main indexes (i.e.pH,O.M., CEC, SiO₂, Al₂O₃,Fe₂O₃, CaCO₃ and clay) of the five soil groups shows that the differences of indexes between soil groups are all significant (F_0.05) or very significant(F_0.05)respectively except pH, CEC and SiO₂ content. In addition, there are also significant differences between soil groups in geographical distribution, vegetation types and calcareous reaction in fields etc.. Each soil group has its marked genetic characters. Compared with genetic classification system, the five soil groups belong to brown earth, leached drab soil, ortho-drab soil, carbonate drab soil and cultivated fluvioaquic soil respectively.