During the Second Opium War,Ruilin,Senggelinqin and other officials were in charge of the reconstruction of Tianjin's de-fense,and used salt tax as additional military supplies and patrol expenses,as well as Tianjin's donations.After the war,to fight against domestic and foreign military threats,Minister Chong Hou,who managed the three ports,recruited soldiers and selected weapons in Tianjin,established a foreign gun army,and repaired the Dagu Battery.The military and patrol expenses for this item have been re-served,and the sources and scale of the funds have gradually expanded,forming a Tianjin coastal defense fund mainly consisting of salt taxes,Tianjin Customs foreign taxes,opium taxes,Tianjin taxes,and East Customs cooperative payments.The coastal defense funds in Tianjin have undergone an evolution from temporary funds to permanent funds,becoming the source of funds for military training and de-fense by the three trade ministers,indicating that the Qing government began to formally establish special funds for coastal defense.