(en) This biography explores the rôle of China's First Lady, Madame Chiang Kai-shek (1898-2003), born Mayling Soong, in the political history of 20th century China and in the evolution of China-U.S. relations, but it also emphasizes the representations that this role generated, leading to the building of a myth in which Madame Chiang ended up as a personification of China for a large segment of the international public opinion. Based on a very large selection of primary sources, unprinted and printed personal testimonies, mostly Chinese and American, but also British, French, Italian, Russian and Indian, this thesis studies Madame Chiang Kai-shek in different perspectives : as a woman in two societies - Chinese and American - which were male-dominated, as a cultural bridge bewteen East and West (she was educated in the U.S. and spoke perfect English), and as a political actor who was much more than the interpreter and secretary of her husband, or than the spokesperson of her country. As this detailed account of her life demonstrates, she was an essential part of the political machine of Nationalist China, both on Mainland China and on Taiwan later on.