第二次鸦片战争以后华北地区的天津、烟台、青岛等城市在列强的胁迫下,被开辟为通商口岸。这些口岸是按照不平等条件被迫开放的,故称约开商埠。值得注意的是,从19世纪末到民国初年,清朝政府和北洋政府先后在华北又陆续把秦皇岛、济南、潍县、龙口、张家口以及绥远的归化等城市辟为自开的通商口岸,从而使华北的自开商埠城市数量 After the Second Opium War, cities such as Tianjin, Yantai and Qingdao in North China were opened up as ports of commerce under the coercion of the powers. These ports were forced to open on the basis of unequal conditions, so they said they would open ports of commerce. It is noteworthy that from the late 19th century to the early Republic of China, the Qing government and the Beiyang government successively set up their own ports of commerce in different cities of Qinhuangdao, Jinan, Weixian, Longkou, Zhangjiakou and Suiyuan in succession in North China. So that North China’s self-opened number of cities