This paper discusses the change on British policy on France from compromise to containment when the Ruhr crisis happened in 1923. It reveals the political and economical reasons. The political reason was British requirement of keeping the balance of Europe, and it didn't want France to crush Germany. At the end of Ruhr crisis, Germany was going to collapse with the pressure of France, and this made Britain resort to containment policy to France instead of compromise policy. The economical reason was that France's controlling Ruhr gradually endangered British interests of coal industry, and was harmful to the development of British industry and internal economy's recovery. This also caused the change of British policy to France.