RESUMEN
Objective: To review the physical characteristics in modern Chinese populations, and to exploring the relationships between physical traits and the geo-environmental factors. Methods: This paper took the principal component and cluster analysis of the craniofacial physical characters of 134 populations in China (65 Han nationalities, 59 minority nationalities and 10 unidentified populations) with 15 measurements. We also focused the linear relationship between the craniofacial measurements and 8 geo-environmental factors. Results: The physical characteristics of Modern Chinese was divided into the northern and southern groups: North Han was close to north minority nationalities; Han nationalities were close to each other in southern region, as well as the minority nationalities. In addition, the physiognomic ear length and physiognomic ear breadth decreased when the annual mean temperature increases, which was not consistent with Allen's rule. Conclusion: The differentiation of northern and southern Chinese population is a result of the physical adaptation which may be caused by the selective pressures under different regional environments. And the north-south demarcation zone (Qinling mountain - Huaihe river) can be considered as the most suitable boundary between the southern and northern Chinese.