Tianjin and East Java are friendly associated on October, 27th,  in 2003.

East Java is a province of Indonesia. It is located on the eastern part of the island of Java and also includes neighboring Madura and islands to the east of it, as well as the Bawean islands. The administrative center of the province is located in Surabaya, the second largest city in Indonesia and a major industrial center and port.

The province has a population of 34,766,000  (2000) within the area of 47，92 2km2.

East Java inhabitants consist of mostly Javanese. Native minorities include migrants from nearby Madura, and distinct Javanese ethnicities such as the Tengger people in Bromo, the Samin and the Osing people in Banyuwangi. It also hosts a significant population of other ethnic groups, such as Chinese, Indians, and Arabs. In addition to the national language, Indonesian, they also speak Javanese. Javanese spoken in the western part of East Java is a recognizably similar dialect to the one spoken in nearby Central Java, with its hierarchy of high, medium, and low registers. But in the eastern cities of Surabaya, Malang, and surrounding areas, the people speak a more egalitarian version of Javanese, with much less regard for hierarchy and a richer vocabulary for vulgarity. In addition to that, Madurese is spoken by around 15 millions of Madurese, concentrated in Madura Island, Kangean Islands, Masalembu Islands, Eastern part of East Java, and East Java main cities.