The Xuecun site is located at the North of Xuecun village in Wangcun township，Xingyang city，Henan province. A total area of 500，000 square meters are covered by the site. Appointed by the Office of Cultural Relics Conservation for the South-to-North Water Diversion project in the Cultural Relics Bureau of Henan Province，Henan Provincial Instrtute of Cultural Relics and Archaeology excavated the Xuecun site in Xingyang city from 2005 to 2006. The excavation revealed a settlement ranging from the late Erlitou culture to the upper layer of the Erligang culture. After the Han Dynasty，the site became a cemetery containing a large number of Han and Tang tombs and some Song，Jin，Yuan and Ming-Qing tombs.
The human skeletons（18 the early Shang，163 Han，52 Tang，30 Song，Jin and Yuan and 64 Ming-Qing）from Xuecun site of Xingyang city have been studied in this paper. In this research，several physical anthropology methods have been used，including demography，stature estimation，human osteology，paleopathology，and statistics. There are seven chapters in this research.
Chapter I introduces the geographical locations and archaeological backgrounds of the Xuecun site in Xingyang city，Henan province. The purpose and the physical anthropology methods have been explained. In addition，this chapter gives a brief description of the concepts about the Ethnic Huaxia and the Ethnic Han and the relationship between them.
Chapter II focuses on the sex ratio，age distribution，mean age at death of the populations from the early Shang period，Han to Ming-Qing periods. On the basis of Han，Tang and Song human skeletons in Xuecun site，and related skeletal samples（14 Han，3 Tang and 49 Song）in other sites of Xinzheng city，this chapter put forward some understandings on the demography of the Ethnic Han of Central Plains Area in Han，Tang and Song periods. A comparison of the average mortality rates on many populations in Central China indicates that the life-spans have been prolonged in the three periods，but the high mortality rates for young women also demonstrates the economic and medical treatment were at a low level.
Chapter III is about stature estimation. In this chapter，body heights have been estimated from the maxium lengths of all the humeri，femora and tibias in adult men and women of the early Shang period，Han to Ming-Qing periods. On the basis of Han，Tang and Song populations in Xuecun site，and related populations in other sites of Xinzheng city，this chapter mainly analyses the statures change in Han，Tang and Song periods. In order to compare male-female difference in body size numerically in Han，Tang and Song periods，an index of sexual dimorphism was computed based on the stature estimates. We can draw a conclusion that in Han，Tang and Song periods，body heights both sexes were becoming increasingly shorter with the times and the difference between both sexes’ contribution to subsistence was little.
Chapter IV is about paleopathology. Trauma（fracture and Schmorl’s nodes），pathologies（osteomyelitis，periostitis，osteoarthritis，ankylosing spondylitis，osteoma，cribra orbitalia and porotic hyperostosis，and avascular necrosis），developmental defects（spondylolysis，septal aperature and sternal aperture）and oral health（caries，abscesses，ante mortem tooth loss，hypoplastic defects and periodontitis）were investigated and analyzed in the skeletal samples from Han to Ming-Qing periods in Xuecun site of Xingyang and from Han，Tang and Song periods in other sites of Xinzheng.
Chapter V uses non-metrical and metrical morphology of ancient human crania to learn the characteristic of cranial shape in the early Shang period，Han to Ming-Qing periods. The physical characteristics of the Xuecun early Shang period crania show that，in racial type，they are closely related to those of modern East Asian Mongoloids. And all the populations in Han to Ming-Qing periods were Asian Mongoloids. The racial type of the populations in Han，Tang and Song periods was closely related to the modern East Asiatic Mongoloids，and skulls（from Xuecun site in Xingyang and other sites in Xinzheng）of the three periods were similar possibly to the modern North Asiatic Mongoloids，the modern South Asiatic Mongoloids and the modern Northeast Asiatic Mongoloids.
Chapter VI uses Average Root-Mean-Square of array differential function，cluster analysis and principal component analysis to compare the population of the early Shang period with other populations of pre-Qin period，and to compare the three groups（from Xuecun site in Xingyang and other sites in Xinzheng）of Han，Tang and Song dynasties with other groups of ancient and modern times，in order to discuss the related problems of those developments about the types and composition of race. In racial type，the population of the early Shang period was closely related to some ancient populations，such as the Wayaogou group and the Youyao group. The element feature of the three groups（from Xuecun site in Xingyang and other sites in Xinzheng）of Han，Tang and Song dynasties was Ancient Central China Type. Maybe，there were some genes of ancient "Qiang" in the Northwest area and ancient nomadic people in the North area in the population of Han dynasty. And there were more genes of alien races in the population of Tang dynasty. But the physical character of the population of Song dynasty was ranging among Ancient Central China Type，Ancient Northeast China Type，Ancient Northeast China Type，etc. The population of Han dynasty looks like the modern South China population. But the two populations of Tang dynasty and the modern South China differ in shape more obviously. And the population of Song dynasty looks more evidently like the modern North China population.
Chapter VII makes a summarized discussion about the whole six chapters.
This research results can provide some informations to the scholars who study the health of populations in Central China and who study the ancient population migrations and the development about the cranial morphological characteristics. The Ethnic Huaxia which mainly composed of the Xia people，Shang people and Zhou people came into being in the medium and later period of the Western Zhou. During the Qin-Han period，Huaxia ethnic group had grown into the Ethnic Han. The procedure of the Ethnic Han developing her own group and assimilating other ethnic groups for more than 2000 years has been studied by many historians，nationalists and humanists. However，the composition of the diverse populations in the Ethnic Han had been changing since Han dynasty and the anthropologists should study the skeletons in antiquity tombs to look into the causes and the course of the changing. As far as the human skeletons researched in this study are concerned，the occurrence and formation of the modern Northern ethnic Han were not earlier than Song dynasty. This analysis in this paper provides reference to discuss the formation and growth of the modern Southern and Northern ethnic Han.
Copyright 2020 Science China Press Co., Ltd. 《中国科学》杂志社有限责任公司 版权所有