This article looks at the efforts China and Iran made towards strengthening themselves and their search for independence and integrity after the First World War. Since the nineteenth century, the two countries had been in a similar situation, under pressure from treaties and rivalries with European powers. The change of the world order brought about by the 1914–18 war created an opportunity for China and Iran to claim back their rights, such as ending extra-territoriality. After the war, the Fourteen Points drawn up by the American president, Woodrow Wilson, gave hope for China and Iran to maintain their independence and integrity. During the Paris Peace Conference of 1919, China and Iran made both gains and losses. China was unable to solve the Shandong Problem but became one of the founding members of the League of Nations, while Iran did not get access to the Peace Conference but obtained Britain’s assurance of independence and integrity by signing the Anglo-Iranian Treaty of 1919, and then joined the League of Nations. China and Iran attempted to bring about cooperation between Asian countries, and therefore signed a treaty in 1920. The significance of the treaty was that the two countries agreed not to grant extra-territoriality to each other, which was what both countries were seeking to achieve at that time.