Whether there is a direct relationship between Xu Yanwang City and the evolution of Dong 'ou State was inconclusive more than 20 years ago. In recent 20 years, through the archaeological excavations of archaeologists in this province and the enthusiastic participation of Taizhou local historians and Wenzhou scholars, it is basically clear that the capital of Dong 'ou and Xu Yanwang are the same ancient imperial capital.
Wang Kewang of Wenzhou and other three people quoted many historical materials in the article "On Building the Capital of Dongou and Moving in", and concluded that "the capital of Donghai King should be in Taizhou, not in Wenzhou" and "the activity center of Dongou is in Taizhou, and the capital is in Huangyan County". One of the historical materials they quoted was Volume 46 of Zhejiang Tongzhi: "Yongning County was renamed Huangyan today, and there is the site of Ou State in the east of Han Dynasty", "Dongou lived in the sea, and Yongning County is also in the sea today". In the fifth year of Ming Chenghua (1469), the south of Huangyan was located in Taiping County, and this ancient city was included in today's Wenling City, not Huangyan. In 1980s, Mr. Jin Zuming of Taizhou Cultural Management Association visited the ancient king city many times and wrote a paper. Huangyan Local Records Office also organized a field trip, agreed with the academic conclusions of Wang Kewang and others, and supplemented the contents. The newly compiled county records include Xu Yanwang City and Dongou Wangcheng.
Zhejiang Institute of Cultural Relics and Archaeology has conducted many investigations and excavations on the ancient king city. The most comprehensive scale of investigation is the archaeological investigation and excavation from September 6, 2002 to June 7, 2002, with an exposed area of more than 200 square meters. The first purpose is whether the site is an ancient city recorded in the literature, and the second purpose is whether the site is the earliest era and the continuation era. The final conclusion of the investigation and excavation is that "the site is an ancient city site", "the upper age of the site should be Song Dynasty, and the lower accumulation of the site should be relics of the Warring States period", and "the ancient city site was only discovered in the Warring States period".
Meng, a famous scholar, recorded in Biography of the Later Han Dynasty in Dongyi that the Xu Yanwang area on the west weekend was surrounded by rivers and Huaihe River, with a circumference of 500 miles, and there were "36 countries facing the DPRK on land", and Dongyue should be one of them. Dong Chuping, a researcher at the Institute of History of the Provincial Academy of Social Sciences, made a new probe into Wuyue culture: "Today, there has been an European country between Huangyan and Wenling." Huang Yan Zhen-fei's History of the Eastern Ou Country records that "Ou" is located in the territory of Dongyue Country in the southeast of Zhejiang Province, and "Yu" is the original word of "Xu", which is a small country expected to be established by people in the middle and late Western Zhou Dynasty. This capital city is the ancient king city of Daxi, and Dong 'ou is the ancient king city after Ou.
Scholars have different conclusions about the value of this ancient city. We can summarize it with a sentence from the investigation and excavation conclusion of provincial cultural relics experts: "Daxi ancient city site is the earliest known ancient city site in Taizhou area, and it is also one of the few cities in our province that have been archaeological investigated and tried to excavate during the Warring States period."