A Summary on the Construction and Extension of the Core Cities from the Early Tang Dynasty to the Middle Song Dynasty

As a critical subject in the research of China's ancient history,the social changes during the Tang and Song Dynasties are typically witnessed by the changes of cities.The construction and extension of cities was a constant national project in ancient China.This article summarizes the stages from the Early Tang Dynasty to the Middle Song Dynasty in constructing and extending the core cities with priority of the capital cities,focusing on the symmetry in urban construction with the eastward movement of political centers and the economic centers' movement to southeast,on the distinctions between the southern and northern cities,and on the noticeable new messages concerning urban development conveyed by the then-people.