New Viewpoints on bio-climatic environmental evolution in Quaternary were proposed based on analysis of physical,chemical,mineralogical composition,spore pollen and micro-morphology studies on soil samples taken at 30~50 cmintervals from Luochuan loess profile dating back to 200,000 BC.The Loess layer(L),formerly interpreted as deposition in arid and cold climate,revealed semi-arid environmental evolution and corresponding soil formation.The red-brown paleosol layer(S),formerly represented warm and humid environment essentially revealed interior arid and semi-arid environmental evolution as shown by contrasting coexistence of both arid and humid type of spore pollen.The present study confirmed that thick Luochuan loess profile is a special multi-paleosol profile system eomprising different soil types and formed by alteration of loess deposition and soil formation in the course of bio-climatic environmental evolution in Quaternary.