About three-quarters of the Yao live in China, mostly in the southern provinces of Guangdong, Guangxi, and Yunnan. The remainder are scattered through northern Vietnam, Laos, and Thailand. Books written thirty years ago mentioned some 130 Yao living in Kiang Tung of Shan State in Burma. It is reported that they have lived in the mountainous areas of China's Hunan province for at least 2,000 years and that they gradually moved southward, probably to Vietnam, as early as the eleventh century to escape from the imperial Chinese administration and to find new hill farmlands. From Laos, some Yao of the Nam Tha areas entered Nan and Chiang Rai provinces of Thailand in the late nineteenth century, and a greater number arrived after World War II.
Young described the Yao as industrious and friendly but shrewd businesspeople eager to trade and to improve their lot. They have considerable contact with their neighbors. Their villages are located among those of different peoples. In the past marriage with the Yunnanese was common; today marriage with other groups still occurs, particularly with Thai men. Since the Yao live at lower elevations than do the Miao and Lisu, their villages are more easily reached by plains-dwelling traders and missionaries. The Yao have frequent contact with the lowland markets, where they buy clothing. Only a few Yao have converted to Christianity. Close contact with Thai society has changed the Yao way of life.