In September through December 1986,an archaeological survey to the Hexi Corridor(excluding Aksay Kazak Autonomous County) was conducted by the joint workgroup consisting of colleagues from Department of Archaeology,Peking University and Gansu Provincial Institute of Cultural Relics and Archaeology.In this large-scale survey,over 40 ancient sites were discovered,most of which belonged to the late Neolithic and Bronze Ages,as well as some belonged to Iron Age or few of which even as late as the Han to Jin Dynasties.The archaeological cultures involved were Majiayao Culture,Banshan-Machang Culture,"Transitional Type" remains,Dongjiatai Culture,Qijia Culture,Siba Culture,Shanma Culture,Shajing Culture and Xindian Culture.This survey and preliminary researches proved that the prehistoric cultures in the eastern section of Hexi Corridor and that in its western section had some differences.In the eastern section of Hexi Corridor,the development sequence of the prehistoric culture was: Majiayao Culture-Banshan Culture-Machang CultureQijia Culture-Dongjiatai Culture-Xindian Culture-Shajing Culture;in the western section of Hexi Corridor,the development sequence of the prehistoric culture was: Majiayao Culture-Machang Culture-"Transitional Type" remains-Siba Culture-Shanma Culture.These archaeological cultures have temporal and spatial coexistence and overlapping in various degrees.The prehistoric cultures in Hexi Corridor,which were originated in the Yellow River and the Huang湟 River Valleys,were the results of the westward emigration and evolution of Majiayao Culture and its subtypes;at last,they traveled into Hami Basin in eastern Xinjiang.In the late Bronze Age,the prehistoric cultures in Hexi Corridor split up into several regional cultures,such as Xindian Culture nearby Tianzhu County at the east end of Hexi Corridor,Shajing Culture in Minqin to Yongchang Basin and Shanma Culture distributed from Zhangye to Dunhuang.These regional cultures kept their isolation for a long time,until Emperor Wudi of the Western Han D