Abstract: Nuanquangou loess section at Longxi basin has been examined in terms of stratigraphic investigation,radiocarbon dating,paleomagnetie polarity,and spore-pollen diagram mineral and chemical analyses.The results indicated that the section is one of acient loess sections with a continuous sedimentation and composed of homogeneous materials with rich-carbonate.Brunhes/Matuyama boundaryand Jaramillo event were recorded in the section.Stratigraphically,this section can be divided into Holocene and pleistocene loesses.The latter included Malan,Lishi and Wueheng loess in descending order.They developed at the age beginning at ca.1.2m.y.Whereas,Nuanquangou section reflects several local characteristics different from those on other areas.