金属器、文字、礼仪性建筑物以及从大型环状壕沟聚落发展到城郭都市的真正出现 ,才能作为中国古代都市文明形成的重要标志。所以说 ,其形成的上限年代并不是相当于夏代的二里头文化 ,而应是河南安阳殷墟文化的晚期。 Metallics, writing, ceremonial buildings, as well as the real appearance of settlements from the large circular moat to the city of Chengguo, can serve as an important symbol of the formation of ancient Chinese urban civilization. So, the upper limit of its formation is not equivalent to the Xia Dynasty Erlitou culture, but should be Anyang Yin Henan ancient culture.