Before port opening

the economic relationship between Tianjin and coastal cities and towns is the interflow of commodities with Niu Zhuang in northeastern coast area

Shanghai in southeastern coast area and coastal cities and towns in Shandong province. After1860

with the opening of ports in Tianjin

Yantai

Qinhuangdao and Qingdao

and the development of domestic and foreign trade

the economic relationship between Tianjin and North China coastal cities and towns began to change. In one aspects

transportation

interflow of commodities and personnel exchange increased between Tianjin and Tanggu

Yantai

Qinhuangdao and Qingdao. In the other aspects

overlap and crossover showed up between Tianjin and Qinhuangdao

Qingdao which resulted in the competition with east Hebei and northwest in Shandong Province. The communication and competition relationship between modern Tianjin and North China coastal cities and towns like Tanggu

Yantai

Qinhuangdao and Qingdao has important influence to coordinated development of Beijing

Tianjin and Hebei Province and cooperation in Circum-Bohai-Sea region in future.