Abstract: The expansion of wheat in ancient northern China has been increasingly discussed and debated in recent years, with a focus on arguments for the temporal-spatial expansion of wheat in a traditional millet-based agricultural area. Some studies show that there is a time difference in the impact of wheat on millet-based agriculture in different areas of northern ancient China. Historical records and archaeological remains indicate that wheat remains were discovered in northern China during the Longshan period. However, it was not until the Eastern Zhou Dynasty and its later periods that wheat affected millet-based agriculture significantly. In order to explore the expansion of wheat in Shanxi Province during the Eastern Zhou Dynasty and its possible impact on human diet and subsistence economy, carbon and nitrogen stable isotopic analyses were performed on human bones from Xiaonanzhuang cemetery, an Eastern Zhou Dynasty cemetery, Jinzhong City, Shanxi Province, China. The results show that δ13C (-9.0‰~-7.5‰, -8.0‰±0.4‰, n=16) and δ15N (9.0‰~11.7‰, 10.5‰±0.9‰, n=16) values are high and concentrated, indicating that people relied primarily on C4 foods coming from millet and animals consuming millet products and/or by-products. Meanwhile, people also consumed some C3 food and had two different consumption patterns for meat. Individuals consuming more meat resources had lives centered on livestock economy, whereas individuals consuming less meat resources made their living mainly by millet agriculture. It can be concluded that C3 foods in the diet of the agricultural population mainly came from wheat, which indicate that the wheat was promoted in the Jinzhong area during the Eastern Zhou Dynasty. The expansion, cultivation and use of wheat in Shanxi Province had a corresponding impact on the traditional millet-based agriculture, which enriched the types of crops. Planting wheat might have accelerated the formation of early Chinese traditional agriculture during the Qin-Han dynasties. However the speed of explosion of wheat in ancient Shanxi is very slow suggesting that there were many obstacles, such as traditional milletbased agriculture and dietary habits.

Key words: methodology; Paleolithic archaeology