Which city is Chang'an City in the Tang Dynasty now

It is now Xi'an.

Chang'an is the ancient name for Xi'an, the first capital city in history to be called the "capital" and the first real city in history.

Expanded Information:

Xi'an, anciently known as Chang'an and Haojing, is the capital city of Shaanxi Province and a sub-provincial city, It is the capital of Shaanxi Province, a sub-provincial city, the core city of Guanzhong Plain Urban Agglomeration, the starting point of the Silk Road, the core area of the "One Belt, One Road", an important center city in western China, and an important national scientific research, education and industrial base.

Xi'an is one of the four great ancient capitals of China, the "World Historic City" identified by the United Nations Educational, Scientific and Cultural Organization (UNESCO) in 1981, and one of the world's top ten ancient capitals selected by the U.S. media. Located in the middle of Guanzhong Plain, it is bordered by Weihe River in the north and Qinling Mountains in the south, with eight waters running through Chang'an.

Under the jurisdiction of 11 districts and 2 counties and administer the Xixian New Area, with a total area of 10,752 square kilometers and a household population of 9,056,800 ?at the end of 2017.

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