The Giay or Zay ethnic group, other names Nhang, Dang, Pau Thin, Pu Na, Cui Chu, Xa are concentrated in Bat Xat, Bao Thang and Muong Khuong districts, Lao Cai Province; Yen Minh and Dong Van districts, Ha Giang Province; Phong Tho and Muong Te districts, Lai Chau Province; and Cao Bang Province.
The Giay ethnic worship not only their ancestors but also the genies of the giayheaven, the earth, and the kitchen, including the Goddess of Childbirth. The Giay villages are very crowded, containing hundreds of households. Houses are built on stilts or on level ground. The central bay of the house serves as a place for receiving guests and for the ancestor altar.
Patriarchal customs rule Giay families. The children take on the family name of their father. The family of a young man usually seeks a marriage for their son. During pregnancy, Giay women must obey certain taboos and a special altar is set up for the delivery.
Giay language belongs to the Tay-Thai Group. The cultural heritage of the Giay is rich including many ancient tales, poems, proverbs, puzzles, and alternating songs.
Men wear trousers, short vests and wind a turban around their heads. Women wear a five-paneled vest open at the side, which buttons under the right armpit, and trousers. They wear their hair wound around their head or wind it in a turban.
The Giay practice rice cultivation in submerged fields and rear animals to provides for additional income. The Giay also rear plenty of horses as pack animals and for transport.