Holoence polycyclic soils were discovered on the Zhouyan tabeland.A typical loess profile is observed by field and soil micromorphology,as well as magnetic susceptibility,grain-size analysis and trace elements.Argillic horizons were identified in the soil and calcification was observed in the loess layer in the profile.It suggests that the Holoence palaeosols S₀² and S₀¹ were formed in warm-wet forest environment. Because of the deposition of a layer(L_x)during the aridity interval between 6 000 and 5 000 aB.P.,the palaeosols S₀,normally associated with the Holoence Megathermal period,is thus separated into two distinct soils,namely palaeosols S₀² and S₀¹.The conclusion is confirmed by the magnetic susceptibility, grain-size and trace elements in the profile.It indicates that the lower soil(S₀²)was formed in the warm-wetest phase in the Holoence in the Guanzhong basin,with the strongest pedogensis,between 8 500 and 6 000 aB.P.The upper soil(S₀¹)was developed in another warm-wet phase when the rainfall was probably lowered slightly between 5 000 and 3 100 aB.P.It has been a relative aridity period during the last 3 100 years,with accelerated aeolia dust deposit.A layer of 40~60 cm thick loess has been accumulated on the Zhouyuan tableland and thus the siol complex has been buried and becomes palaeosol of the Holoence.