Abstract: The Dongzhao Site, located in Zhengzhou City, Henan Province contains different cultural remains dated from late Longshan to Zhou Dynasty. In this site, three city wall ruins of different sizes were recovered belonging to the periods of Xinzhai, Erlitou and Dongzhou respectively. For its crucial geographic location and time range, the Dongzhao Site plays an important role in studies of the development of civilization and state origins in central China between 2500-1500BC. In this paper, abundant carbonized plant remains belonging to Xinzhai, Erlitou and Erligang periods were analyzed which included charred wood pieces, nut shells and plant seeds. The statistical results show that crop seeds dominated these carbonized plant remains, which included foxtail millet (Setaria italica), broomcorn millet (Panicum miliaceum), rice (Oryza sativa), wheat (Triticum aestivum) and soybean (Glycine). In addition, Foxtail, Tares, Crabgrasses and some other weed seeds were also recovered in the Dongzhao Site. The research results indicate that dry farming of foxtail millet and broomcorn millet is the dominant agricultural pattern in the Dongzhao Site during the entire period from the late Longshan to the East Zhou Dynasty. It is worth noting that past populations in Dongzhao began to cultivate rice, wheat and soybean from the Erlitou period, indicating the formation of a new agricultural pattern with many different crops. Furthermore, analysis of the proportional presence of all crops and related weed seeds also shows that continuous progress was made in agricultural development and field management techniques in the Dongzhao Site. All of these findings have great significance for understanding the development of Chinese civilization and state origin between 2500BC to 1500 BC in central China.

Key words: Dongzhao Site; Flotation; Xinzhai period; Erligang Period; Plant remains; Evolution of agricultural patterns