The Guanganmen area is the locality of the ancient Jicheng city (the earliest city site in Beijing). Based on the geomorphological analysis and the several kinds of experiments for the samples collected from the geotechnical profile in the construction site of Guangyi Building in Guanganmen area, the reconstructions of palaeogeomology in this area were conducted. The results show that the location of the ancient Jicheng city was just the highland, which developed since the Holocene, beside the river, where the channel of Yongding River has been passed through about 22000 years ago. The climate in this area has changed from the cool and wet environment (sparse-wood grassland was developed) and the following arid environment (grassland vegetation was developed) in the late Late-Pleistocene to the warm and wet environment (sparse-wood grassland was developed) and the following cool and wet conditions (meadow vegetation was developed) during the Holocene.

By analyzing results of routine soil test about the site of State Beijing Grand Theater and the other several sites around State Beijing Grand Theater and observing the geo-technical sections in situ, the authors analyzed the general characters of recently deposited soil in State Beijing Grand Theater area, studied the relativity of several key indexes by the statistical method, and indicated that void characters of soil is one of the key factors which affect property of recently deposited soil.

Prehistoric cataclysms and their impacts on human paleo-culture have been a focus of the scientists in the world. Some ancient trees relatively undamaged back, roots and branches were unearthed from paleochannel in the Peking University campus. The burying position, the characteristics and the age of the trees indicate that the flowage of ancient Yongding River resulted in the event at about 5000a B P. The trees, together with the Neolithic culture relic unearthed at the same time, show that the disastrous floods definitely occurred at about 5000a B P in Peking area.

The sedimentary characteristics and facies of the cultural layers in the late Paleolithic period of the late Late-Pleistocene in the Wangfujing Oriental Plaza site were studied based on the comparison and analysis of the typical sedimentation profile of the site and more than 150 stratigraphic data. The paleo-geomorphic surfaces during the periods of 2.2×10⁴ a B.P. were rediscovered. The study suggests that the ancients must have acted in the sandy islands of alluvial fans, which were evolved in relatively steady water flows during the interglacial stage with slightly warming in the last glacial epoch. The cause of the absent of human activities between the upper and lower cultural layers in an interval of about 3.14×10³ a has also been discussed in detail. It is concluded that this was resulted from the strengthening and unstable water flow. The potential former settlements or camping sites of the ancients prior to moving to this area are also discussed. It is suggested that they might came from other higher dissected old alluvial fan platforms evolved at the same period or earlier in the western part of the plain. These results provide evidences for the reconstruction of the geomorphic environment of Beijing plain during the Late Pleistocene and the study of prehistoric human history.

The Paleolithic site found in Dongfang Square Wangfujing in Beijing is a late Paleolithic cultural site. It consists of two cultural layers. The TL age of the sample from the upper layer we obtained is (1.5- 1.9)×10⁴a B.P. and the age of the lower layer is (2.2- 2.6)×10⁴a B.P.. This site is located on a plaeo-levee of a river and is a place of ancient human activity during a short period. This discovery has a important significance for studying the relationship between human active history and paleoenvironment evolution on Beijing Plain.