Abstract: Jiangxigou archaeological site is located in northeastern margin of the Qinghai-Tibet Plateau (QTP). This section is an important Microlith relic site with consecutive strata. Here we present an integrated study on multi-proxy including human activities index (stone, animal bones and pottery shreds) and environmental index (magnetic susceptibility, color and pollen) of this section. The results show that the occurrence of Microlith has a close relationship with environmental change. In the Holocene, Microlith hunters lived in an Artemisia dominant environment. Before 9 ka BP, human activities initiated to appear on the QTP due to the increasing improvement of the early Holocene climate. After 9 ka BP, steppe vegetation was well developed under the optimal climate of this time, which supplied abundant foods for hunters, and thus promoting Microlith culture into the prosperous period. Since 6 ka BP, as the deterioration of the climate, the Microlith culture began to decay. Pollen analysis indicates that relatively high content of Poaceae and the attendent weedy plants might relate to the human activities. The proportion of Poaceae reached its highest level during 6.7-4 ka BP, which was corresponding to the stage when pottery shreds were widely used. We suggest that these facts would relate to the crop cultivation during this time. The occurrence of pottery shreds was probably associated with the farming activities of ancient people. Based on these records, we conclude that the culture in the northeastern margin of the QTP was Microlith culture before 6 ka BP and has changed since then. After 6 ka BP, the Microlith hunters lived at higher elevations of the plateau while the farmers occupied the valley regions at relatively low altitudes.

Key words: the northeastern margin of Qinghai-Tibet Plateau, human activity, environment