Name of Ethnic Group: Si La (Cu De Xu).

Population: About 600 people.

Locality: Lai Chau Province.

Customs and Habits: The Si La live in houses built level to the ground. The kitchen is usually placed at the centre of the house. Relationships between the members of a lineage are very close. The head of a lineage is usually the oldest man who plays an important role in the village. He also acts as a leader in charge of internal affairs, and especially during worship. The "mo" (sorcerers) are well respected. The Si La wedding ceremony is celebrated in two stages with one year passing  in between the stages. The family of the groom must hand wedding presents to the bride's family prior to meeting the bride and bringing her home.

The burial ground of the dead occupies a plot at the end of the village. Graves of members of the same lineages are grouped together. The Si La often build the funeral house for the dead first, then dig the grave for the house. The coffin is made from a hollowed tree trunk. When a person dies, the Si La organize different kinds of ceremonies. They never clean the graves or exhume the dead's remains, but they maintain the custom of mourning their parents for three years. The Si La also worship their ancestors and the spirits of the village.

Culture: The Si La language belongs to the Tibeto-Burman Group.

Costumes: The attire of women is quite unique. The upper part of their dresses are different colors and decorated with silver and tin coins. Their headgear varies according to age. When travelling, they always carry a woven handbag with red fringes attached to the hems of the handbag. In the past, men have painted their teeth red and women have painted theirs black. This custom is no longer observed by the young people.

Economy: The main forms of income are rice and corn cultivation. Hunting and gathering are also a significant part of the life of the Si La.