The history of the Yi people can be traced back to the era of the Yellow Emperor (about 2570-2550 BC, Chronology of Three Emperors and Five Emperors). Chinese literature: The History of Taoism Volume II quotes Tongli: "Rehmannia takes 30th as the month and November as the winter solstice". Scholar Yi Mouyuan's Study on the Ancient Universe View and Calendar of the Yi Nationality quotes the book Credit Bean Quepu and Xu Zubai compiled by the Planning Office of the Ancient Books of Yunnan Ethnic Minorities (87 pages, Yunnan Ethnic Publishing House, 1987): "The compilation of the Yi people's inheritance of the year, month, day and time began in' Rehmannia': December of one year. Twelve o'clock in the day and twelve o'clock in the evening. All day long, from now on, half and half. After these points, it is divided into spring and summer and autumn and winter. There are four seasons in a year, and they are distinct. The days are long and short, and there are solar terms in the year, all of which are rehmannia. " It can be seen that the legends of the Yi nationality mention the Yellow Emperor by name in the legends of the Han nationality, and the Han literature and the legends of the Yi nationality say in unison that "the 30th is the January of the Yellow Emperor", which can't be explained by "coincidence" in any case, but can only be explained as: the existence of secular monarchs is real, and the embryonic form of the Yi nationality has already existed in the era of the Yellow Emperor. According to the chronology of the Three Emperors and Five Emperors, the early Yi people existed 4500 years ago. Nationalities did not exist at the beginning, such as the Han nationality, which was formed in the Han Dynasty on the basis of the Chinese nationality in the pre-Qin period and through the integration of many nationalities. Yi people live in the southwest mountainous area, and the terrain is closed, and the situation of communication and integration may be much less than that of Han people. I believe that she is a nation of relatively simple ancestry. 4,500 years can be passed down from generation to generation, and it should be one of the oldest ethnic groups in China.