中文摘要：

三棵树旧石器遗址发现于河北省阳原县东谷坨村东北部。2008年秋，该遗址经过小规模试掘，出土251件石制品及一些碎骨和牙化石。石制品包括石核、石片、工具和断块、碎片等；工具有刮削器、尖状器、端刮器、凹缺器、锯齿刃器、雕刻器、石锥、石钻、鸟喙状器等。石制品以小中型为主，其原料主要为石英砂岩、石英、燧石、白云岩、玄武岩等，全部为就地取材。三棵树遗址与后沟遗址同处泥河湾层上部，处于后沟遗址下部和马梁遗址上部，时代属于中更新世中后期。该遗址的发现有助于探讨我国华北小石器文化发展脉络以及探索细石器文化传统渊源。

英文摘要：

The Sankeshu Paleolithic site was discovered in the northeast area of Donggutuo village, Yangyuan County, Hebei Province. From a test excavation in autumn of 2008, 251 stone artifacts and some fragmentary bones and teeth were unearthed in four cultural layers. The artifacts included： cores, flakes, tools, chunks and debris, with tools represented by scrapers, points, endscrapers, notches, denticulates, burins, awls and borers. Endscrapers and notches were common in lay artifacts were small chert, dolomite and ers 4 and 5. Six ＂DGT cores＂ were found in layers 4-6. Most of stone and middle sized. Raw material was mainly quartzose sandstone, quartz, basalt, which were common in local bedrock and cobbles. Like the Hougou site, the Sankeshu site is also located in the upper part of the Nihewan Beds and thus belongs to a rarely found late period site in this area. This site is situated just below the Hougou site and above the Maliang site, and therefore the age of the site should be later than the former but earlier than the latter. Considering the cultural features, materials from this site can reasonably belong to the middle or late period of the Middle Pleistocene. The discovery of ＂ DGT cores＂ here strengthens the significance of this site for discussing tradition of small tool industry including microlithic culture in north China.