The work of "Vietnam Ethnic Communities" is composed of 4 books. Volume One: The ethnic groups of Viet - Muong language. Volume Two: The ethnic groups of Tay - Kadai language. Volume Three: The ethnic groups of Mon - Khmer language. Volume Four: The ethnic groups of Hmong - Dao; Tibetan - Burmese; Malay - Polynesian language. In the Volume Two that you are holding the authors presented a research situation of each ethnic community of this Tay - Kadai language including 12 ethnic minorities: Tay, Thai, Nung, San Chay (Cao Lan - San Chi), Giay, Lao, Lu, Bo Y, La Chi, La Ha, Co Lao, Pu Peo and provided a readership with economic activities, social & cultural life and changes that took place in the new conditions.