Abstract: The paper on palynology and archaeology reveals the living environment of ancestor and the mutual relationship between human activity and environment change by pollen analysis of Qiguoshan Section in Chifeng Area. The results show that 8 400-6 200 a B.P., the climate was warm and moist with grassland vegetation, ancestors did hunting, fishing, planting and herding; 6 200-4 000 a B.P., environment changed gradually bad, and the agriculture level dropped with destroying forest; 4 000-2 500 a B.P., climate was temperate and arid with grassland vegetation, ancestors planted dry crop; 2 500 a B.P.-today, vegetation was the typical grassland of Artemisia, with comparatively temperate arid climate, the agriculture and animal husbandry was comparatively developed, and influences of human activities on environment have been enhanced.