Poor hygiene was a serious problem in late Qing and early Republic China. Some books and articles have been written on this subject, but they do not focus on Canton. The modern health and hygiene movement in Canton is not well researched. 1 This chapter focuses on how American medical missionaries encouraged the Cantonese to change their unhygienic habits and to improve the unsanitary environment of Canton, conducted vaccination work, fought the plague, treated opium addicts and lepers, and promoted rural hygiene and health work. This chapter also studies how the Cantonese elites, encouraged by Americans and impressed by Western preventive medicines and measures to some degree, advocated sanitary modernization, and how the Cantonese medical professionals and the Canton government worked together to launch a public health and hygiene movement in Canton in the 1920s and 1930s.