The Yellow River headwater basin located in the northeast Tibetan Plateau is the source of the Yellow River. In this paper, the authors analyzed the pollen in the fluvial and lacustrine facies sediments in the Yellow River headwater basin. The pollen assemblage includes herbaceous pollen (Asteraceae, Artemisia families, Chenopodiaceae, Gramineae) and woody pollen (pine, birch). An analysis of characteristics of various kinds of plant pollen revealed the evolution and change of the palaeovegetation and palaeoclimate in Yellow River headwater basin since the Early Pliocene.oft-com:office:office" />