This paper aims to clarify the diplomatic relations between Japan and Britain in the end of the Edo period from the viewpoint of Britain. In Japan, the hostilities between the Tokugawa shogunate which was the Japanese feudal government from 17th to 19th century and several feudal lords like the Choshu clan came out into the open in the 1860s. The Tokugawa shogunate sent their troops to the Choshu clan territory, and in the end the war broke out in 1866. According to one popular theory, it have been thought that the French supported the Tokugawa shogunate while the Britain supported the Choshu clan. However, previous studies say that the British government would take a stance of the neutrality in their hostilities. In fact, there are some diplomatic dispatches, which the British consul general to Japan reported to British Government that recommended a policy of accommodation to both the Tokugawa shogunate and the Choshu clan. In addition, there are some articles in the British newspapers, which denied that British Government supported the Choshu clan. Therefore, this paper reveals the details of the diplomatic relations between Japan and Britain by an analysis of dispatches from the British consul general to Japan and British Newspaper articles in 1865 right before the war in Japan.