Tianjin, historically romanized as Tientsin, is a municipality and a coastal metropolis in Northern China on the shore of the Bohai Sea. It is one of the nine national central cities in Mainland China, with a total population estimated at 15,621,200 in 2016. Part of the Bohai Economic Rim, it is the largest coastal city in northern China. In terms of the urban population, Tianjin is the fourth largest in China, after Shanghai, Beijing, and Guangzhou.

In terms of administrative area population, Tianjin ranks fifth in Mainland China. The walled city of Tianjin was built in 1404. As a treaty port since 1860, Tianjin has been a major seaport and gateway to Beijing. During the Boxer Rebellion, the city was the seat of the Tianjin Provisional Government.

Under the Qing dynasty and the Republic of China, Tianjin became one of the largest cities in the region. After the founding of the People's Republic of China, Tianjin suffered a depression due to the policy of the central government and the Tangshan earthquake but recovered from the 1990s. Since 2010, Tianjin's Yujiapu Financial District has become known as China's Manhattan. Another is that it honours a former name of the girl, a Chinese constellation recorded under the name Tianjin in the Astronomical Record section of the Book of Sui.

The most common is that it was bestowed by the Yongle Emperor of the Ming, who crossed Tianjin's Gu River on his way south to overthrow his nephew the Jianwen Emperor.

• GDP: RMB 433.77 billion
• GDP per Capita: RMB 41,629
• Per Capita Disposable Income of Urban Residents: RMB14, 283
• Economic Growth Rate: 14.4%
• Population: 6.97 million (urban), 3.78million (rural)
• FDI: US$4.13 billion
• Annual Average Salary/Wage: RMB 27,252
• Government Effectiveness Rating: 64th
• 2006 Chinese Cities Competitive Rating: 12th

Tianjin is one of the first Chinese cities to come in contact with modern western civilizations. After 1860, Tianjin became a pioneer of opening in the north and a base of “Westernization Movement”, breaking new grounds in military modernization and the development of railway, telegraph, telephone, modern education, etc

The total land area of Tianjin is 11,916.9 square kilometres, consisting mainly of plains and lowlands. Constructional plain accounts for 93% of the total area of Tianjin

Tianjin is located on the west coast of the Pacific Ocean, in the convergence zone of the Beijing-Tianjin-Hebei Urban Agglomeration and the Bohai-Rim Economic Circle.

Tianjin is divided into 16 county-level divisions, which are all districts.  In addition, the Tianjin Economic and Technological Development Area (TEDA) is not a formal level of administration, but nevertheless enjoys rights similar to a regular district. At the end of 2017, the total population of Tianjin is 15.57 million.

These districts and counties are further subdivided, as of December 31, 2004, into 240 township-level divisions, including 120 towns, 18 townships, 2 ethnic townships and 100 subdistricts.

Tianjin's GDP reached 1.572 trillion yuan in 2014, an increase of 10.0% over 2013. The city of Tianjin recorded China's highest per-capita GDP at $17,126, followed by Beijing with $16,278 and Shanghai with $15,847. Major industries include petrochemical industries, textiles, car manufacturing, mechanical industries, and metalworking.

Tianjin Economic and Technological Development Area
As one of the first state-level economic and technological development zones, Tianjin Economic-Technological Development Area was founded on December 6, 1984, with the approval of the State Council.

Tianjin Export Processing Zone
The central government granted this special economic zone special preferential policies to attract enterprises in the business of processing and trade to invest in the zone. Tianjin Export Processing Zone is located to the northeast of TEDA with a planned area of 2.54 km2. The area developed in the first phase is 1 m2.

Tianjin Nangang Industrial Zone
The total planned area of Nangang Industrial Zone is 200 km2, of which the terrestrial area is 162 km2.

Resources
Geothermal energy is another resource of Tianjin. Deposits of manganese and boron under Tianjin were the first to be found in China.

Binhai New Area
Tianjin Binhai New Area is located in the juncture of the Beijing-Tianjin City Belt and the Circum-Bohai City Belt.
 

Following the trend of global intelligent information, Tianjin has accelerated the construction of new-generation information infrastructure, promoted the intelligent transformation of urban public infrastructure, and comprehensively upgraded the capacity of urban infrastructure services. Wireless public LANs in large public places are free to the public, with more than 20,000 access points.