Abstract: The Xujiacheng Paleolithic site is located in Xujiacheng village, Wanquan Town, Zhuanglang County, Gansu Province. This site was buried in the Malan Loess overlying the second terrace of the Shuiluo River.It was discovered in June 29, 2009, and excavated from July 10 to August 25 by staff of the Institute of Vertebrate Paleontology and Paleoanthropology and the Gansu Provincial Institute of Archaeology who together exposed an excavated area of about 15m2.
Nine stratigraphic layers were identified at this site, with total thickness of more than 6.5m. Archaeological materials were mainly unearthed from the 4th and 5th layers. According to the distribution of stone artifacts and fossils in the profile, four cultural layers were identified and more than 5500 stone artifacts and 550 fossils were unearthed.
The stone assemblage included manuports(N=385), cores(N=140), flakes(N=1341), chunks(N=688), debris(N=2689) and retouched tools(N=176). The stone artifacts from four different cultural layers showed roughly similar features. The general characteristics of these artifacts are summarized as follows: 1) Lithic materials exploited at the site were locally available from the ancient riverbed with more than eight kinds of raw materials utilized in core reduction and tool manufacture. They are granite, quartz, conglomerate, diorite, marble, quartzite, gabbro and amphibolite. Quartz and granite were the dominant raw materials used for producing stone artifacts at this site. 2) The principal flaking technique was direct hammer percussion without core preparation, and occasional use of bipolar technique. 3) Most stone artifacts were small and medium in size. 4) Only five types of retouched tools were identified, namely side scrapers, points, drills, choppers, and notches. Denticulates, endscraper, drill scrapers, notched scrapers may have existed. 5) Major blanks for tools were flakes, then chunks, and rarely pebble blanks.
The stone tool assemblage of this site shows close ties with the Flake Tool Industry(Main Industry) of North China.Based on stratigraphic observations and AMS14C dating, the main cultural layers of this site are suggested to be 36ka-43ka BP(uncal).

Key words: Gansu Province; Shuiluo River; Xujiacheng site; Stone artifacts; Late Pleistocene