In 2001, a full-coverage field survey was carried out to explore sites of the Xinglongwa, Zhaobaogou, Hongshan and Xiaoheyan cultures in the lower Banghe River and the upper Laohushan River valleys in Aohan Banner, Inner Mongolia. The aim of the project was, in the perspective of settlernent archaeology, to inquire into the development of social complexity in the two valleys. The data from the lower Banghe River valley show a sharp increase of settlements both in size and in number in the middle Hongshan period. Twenty-three Hongshan sites with a total area of 75.4 ha were found. Moreover, their variety in grade suggests considerable social complexity. In the upper Laohushan River valley, almost no residential sites were recorded except for seven sacrificial sites. This, following the discovery of the Niuheliang ritual complex, again demonstrates the existence of exclusive sacred places separated from everyday secular life.
In 2002- 2003, the First Inner Mongolian Archaeological Team, IA, CASS, carried out two seasons of excavation on the Xinglonggou site. The work resulted in the confirmation of the first locality as a large-sized settlement of the middle Xinglongwa culture (8000-7500 BP). The significant findings in dwelling form, settlement layout, burial custom, primitive religion, economic formation and environmental archaeology represent a new type in the Xinglongwa culture. The second locality is left over from a small-sized ditch-surrounded settlement of the Hongshan culture (5500-5000 BP). Its discovery made up the gap of late Hongshan Culture sites in the prehistoric data. The third locality remains of a small-sized ditch-surrounded settlement of the Lower Xiajiadian culture (4000-3500BP), which offers new material for studying the civilizing course and early state form of the West Liaohe River valley. The excavation of the Xinglonggou site will forcefully promote the deep-going study of prehistoric archaeological cultures in Northeast China and exert active influence upon the research on Sino-Japanese cultural relations in prehistoric times.
