Abstract: In this work,the ‘Red Clay’ deposit underlying the typical loess-paleosol sequence at Luochuan,central Chinese Loess Plateau,is studied on magnetostratigraphy,grain size distribution and magnetic susceptibility.It shows that aeolian deposit of the late Cenozoic at Luochuan,the National Loess Park,started at least since 3.2 Ma before present.Proxy index of paleoclimate of this aeolian sequence such as grain size distribution and magnetic susceptibility indicates that the paleoclimate was relatively warmer and less varied during the late Pliocene than that of the loess deposit during the Quaternary period and there was a significant climate shifting that took place around 2.6 MaBP,the boundary of the Pliocene and Pleistocene in North China.