The ancient Chinese capital was developed from a single palace city to the coexistence of a palace city and an outer city and finally to the triple-city form with a palace, an inner and an outer cities. The city gates of a capital were its marking buildings; the main gates of the outer, inner and palace cities were generally on a straight line, which was the central axis of the capital. The main streets leading to the city gates along with other roads formed the “skeleton” of the whole city and demarcated its different areas. Ceremonial buildings constituted an important part of an ancient capital; the change of their location in the capital and the alteration of their form reflected the transformation of their political position. Archaeological researches on ancient capitals should be carried out by combining the macroscopic with the microscopic and pay great attention to material evidence of a political nature in both field excavations and indoor studies.
A capital of a dynasty was the epitome of its whole politics,economy and culture of a dynasty .As a result ,the research of ancient capital sites should be an important field of Chinese historic archaeology.Imperial palace was the political center of the capital,so the research of palace sites could be taken as an especially important aspect of the study of capitals.As the main arena of the national political life,palaces were always the symbolic buildings of kingship and imperial power.Taking the character of archaeclogy into account, palaces can be chosen as a cut- in pointto study the problems such as the emergence of ancient civilizations and the forming of ancientstates. In historical studies,greatimportance should be attached to the problems such as the shapes of palaces in different times,the evolvement of palace layout,and the relation between the palace and the whole city,etc.The architectural plane of ancientpalace is mainly designed to be oblong, square and roundness ( or polygon) .The former was always chosen as the plane shape of palaces.the imperial mausoleum buildings,and the religious buildings.while the latter two were always applied to ceremonial buildings (礼制建筑 ) .Ceremonial buildings could be distinguitshed from palaces during the later period of Xia dynasty(夏代 ) at the latest.It was during the Shang dynasty (商代 ) that palaces and ceremonial buildings began to be placed in different districts.This custom was followed by most states of the Eastern- zhou period (东周时期 ) Through Qin(秦代 ) and Han dynasty(汉代 ) ,it was practiced as a rule in the architectural layout of capitals.This process shows us that religious authority gradually became an appendage of the kingship and imperial