The traditional social organisation of the Hmong is based on the clan. Each clan is made of lineages, all the members of which acknowledge a common founding male ancestor.
The main subgroups present in Vietnam are the White Hmong, the Hmong Leng, Hmong Pua, Hmong Shi or Sheu and the black Hmong. In Sa Pa, the Hmong Leng are the most numerous.Originally, the Chinese hmong populations used to live in the wide plains south of the Yangtse river. As of the 16th century, they started to migrate to the south-east under the demographic, territorial and political pressure of the Chinese.
During the first half of the 19th century, the Hmong left the Chinese territory and settled in neighbouring countries. At the time, the great Taiping rebellion (1850-1872) was disturbing all southern China (Guizhou, Yunnan and Sichuan provinces) causing long periods of famine that pushed numerous ethnic groups to go south. The Hmong entered the Indo-Chinese peninsula through North Vietnam, their presence near Lai Chau was reported in 1848. These successive waves of migration were probably facilitated by the hmong tradition of shifting cultivation and their close contacts with the Chinese caravaneers who had been travelling for centuries through the mountains of southern Asia.
Today, the traditional agrarian economy is still based on family farms raising pigs, chickens, buffaloes and horses, on food crops (rice, corn, manioc) and cash crops (cardamom and vegetables).The traditional social organisation of the Hmong is based on the clan. Each clan is made of lineages, all the members of which acknowledge a common founding male ancestor. In the Hmong household, up to four different generations may be gathered under the same roof. The household is the most important economic, political and ritual unit. The villages perched on the mountain slopes house several clans.