本文对2015年发现的前上营遗址B地点(QSY-B）的地貌地层发育、年代、遗物埋藏特点和出土石制品的技术特征进行报道。地貌和沉积物特点表明，该遗址的地层记录了泥河湾古湖扩张-收缩-扩张和消亡的过程，古人类活动于古湖水退去的湖滨相环境，顶部覆盖马兰期黄土。前上营遗址B地点为古人类单次活动、短暂停留形成的遗址，较弱的水流运动改变了标本的空间分布，但遗物组合较为完整。沉积物ESR年代测定表明，古人类在该遗址的活动时间大致为距今429±39 ka，处在中更新世。原料调查显示，古人类从距离遗址7~8 km以外区域获取石料，岩性以火山岩和硅质白云岩为主。古人类主要采用锤击法剥片，石核剥片效率和石片产出率高，部分石片显示边缘使用痕迹；多样化的修理石器是该遗址不同于盆地内早更新世石器工业的主要特点，表明古人类对资源环境的适应性及灵活的技术策略。动物化石表面保留人为割切痕迹，指示古人类对动物资源利用行为。前上营遗址B地点的发现和研究，对解读中更新世中国北方古人类的技术行为，以及探讨泥河湾盆地古人类在早－中更新世石器技术演变及适应策略具有重要意义。

The Nihewan Basin of northern China preserves extensive Quaternary fluvio-lacustrine and loess sequences and hosts one of the highest concentrations of Palaeolithic sites in East Asia. While Early Pleistocene hominin activity in this region has been extensively studied, Middle Pleistocene sites remain rare and less understood. This study reports new evidence from the Locality B of Qianshangying site (QSY-B), discovered in 2015, with a focus on its geology, stratigraphy, chronology, stone artifacts assemblage, and human lithic technological strategies.

Geomorphological and sedimentological data show that the archaeo-stratigraphic sequence captures a full cycle of lake expansion, retreat, re-expansion, and final regression of the Nihewan paleolake, capped by Malan loess. Hominin occupation occurred in a marginal lacustrine setting during a low lake-level episode. QSY-B represents a brief, single-phase occupation, with minor post-depositional disturbance by gentle hydraulic event. The integrity of the assemblage allows for detailed technological and behavioral reconstruction.

ESR dating of sediments from the archaeological layer suggests that hominins occupied the site around 429 ± 39 ka, placing it firmly within the Middle Pleistocene. Geological surveys indicate that hominins procured raw materials—primarily lava and siliceous dolomite—from source 7-8 km away from the site. The lithic assemblage is marked by hard-hammer percussion, efficient core reduction, and abundant flakes, which bear traces of direct use without modification. A notable feature is the diverse range of retouched tools, contrasting with Early Pleistocene local industries and suggesting increased technological flexibility and environmental adaptability of early humans.

Faunal remains bearing cut marks further attest to animal processing activities. The findings from QSY-B enhance our understanding of hominin behavior during the Middle Pleistocene and offer new perspectives on the long sequence of technological evolution and adaptive strategies of early humans in the Nihewan Basin.