This paper undertook the C and N stable isotopic analysis of human bones unearthed at the Gouwan site in Xichuan,Henan,to reveal the human diets and to explore the lifestyle of humans and the development of rice and millet agriculture.The contribution of rice to human diets was almost equal to that of millet in this site though millet agriculture is the traditional economic model for the middle Yellow River Valley.On the other hand,the comparison of C and N stable isotopes in different cultural periods clea...