Abstract: The Yandunbao Paleolithic site, situated at the fourth terrace of the Yangtze River, was discovered in 1994 and later excavated for four times. More than 1300 pieces of stone artifacts and some pieces of pottery were collected from the site. Some lithic artifacts were unearthed from primary context in a layer of Laterite-like clay at the bottom of the deposits, estimated to be the late Lower Pleistocene, while some stone artifacts and ceramics were found in secondary context in a layer of fine sands and a layer of sandy clays on top of the primary cultural level. Analyses on sediments and artifacts indicate that stone artifacts encountered from these three levels belong to the same cultural horizon. The general characteristics of the stone assemblage are summarized as follows:
1) The stone assemblage is mainly composed of medium and large ones in size.
2) The main raw materials used for stone tool manufactory are quartzite and sandstone cobbles locally available on the river bed.
3) Artifact types include hammers, cores, flakes, retouched tools and chunks. More than half of them are flakes.
4) Most cores are single-platform ones with cortical surfaces. Flaking is accomplished by hammer percussion. Cores were flaked simply and casually, indicating low extent of consumption.
5) More than seven percent of the stone artifacts are retouched tools, mainly scrapers and chopper-chopping-tools. Some notches, end scrapers, points and burins are also present. Retouches on these tools are overwhelmingly unidirectional.
The paper points out that local paleoecological system played an important role in shaping the characteristics of the stone assemblages at the Yandunbao site. The site lies on the bank of the Yangtze River and its surroundings are rich in animal and plant food resources, and the abundant rounded large cobbles on the river bed provide handy raw materials for stone tool making. This stone assemblage exhibits the main characteristics of the Pebble-tool industry in South China. Therefore, the Yandunbao industry provides new data for the study of hominid adaptation patterns and the development of the Lower Paleolithic pebble-tool tradition in China.

Key words: Stone assemblage; Three Gorges region; Yandunbao site; Lower Paleolithic