<p>The Liaohe River Valley was one of the key centers of the origination and development of agriculture in northern China during the Holocene. To understand the long-term interaction among the evolutions of climate, agriculture, and human activities, it is essential to quantitatively reconstruct the spatiotemporal changes in regional prehistoric human land use. In this study, known archaeological sites and a prehistoric land use model (PLUM) were combined to reconstruct changes in land use in the Liaohe River Valley during 8–2 ka BP from a quantitative perspective. The land use area experienced two stages of increase (during 8–5 ka BP and after 4 ka BP) and one stage of decrease (during 5–4 ka BP); these periods were characterized by spatial expansions and contractions. The land use intensity level differed significantly in the western and eastern parts of the valley before 4 ka BP, but the situation changed as the distribution center of the human activity shifted to the southern part of the valley around 5–4 ka BP. Overall, the spatial and temporal changes in the land use areas in both the western and eastern parts of the valley responded well to variations in precipitation during 8–2 ka BP, which potentially provides useful insights into understanding the responses of human activity to future climate change.</p>