中文摘要：

晚更新世以来,史前人类有3次向青藏高原东北缘扩张的历程,均与环境演变有密切的关系,第一次进军高原发生在40-30ka BP暖湿的气候背景下,其后由于LGM严酷的自然环境,人们在高原的活动极大萎缩,出现文化断层 末次冰消期迅速好转的自然环境驱动了向高原的第二次进军,其后持续暖湿的自然环境,保证了人们能在高原生存与扩散 6～4ka BP东部毗邻地区的马家窑居民,在全新世暖期的气候背景下再次进入东北缘,促使原先生活在高原的居民告别了旧石器时代,进入新石器时代,社会性质发生巨大提升。

英文摘要：

Prehistoric human had moved forward northeast margin of Tibetan Plateau three times since Late Pleistocene, these activities are closely related to environmental evolution. The first expansion took place in 40-30 kaBP under warm-humid climate background; later, owing to the hard natural environment of Last Glacial Maximum, human activities have greatly shrunk at the plateau, and the cultural gap emerged. The rapid improvement of the natural environment driven the second expansion moved forward to the northeast margin of the Tibetan Plateau in the last deglaciation, then, persistent warm-humid climate is the guarantee of human survival and diffusion at the plateau. Majiayao culture at the east neighbourhood in 6-4 kaBP, under Holocene megathermal period background, came into the northeast of the Tibetan Plateau again, promoted the residents living on the Plateau before the end of Paleolithic and entered Neolithic Age, the social nature generated a huge progress.