The following is a short Hmong folk tale which tells how the 18 Hmong clans received their names. The folk tale is only one version of a story that takes many forms:

"A very long time ago, the whole universe turned upside down. The earth tipped up, and the sky rolled over, and the whole world was flooded with water. All living things were killed, except one brother and his sister, who had ran and taken refuge in an unusually large wooden and funeral drum. The brother and sister married each other and lived together as husband and wife. Later, they gave birth to a child. This child was like a round smooth stone. They cut the round egg-like child into little pieces. Then they threw the pieces in all directions. Two pieces fell on the goat house and these became the clan Lee. Two pieces fell in the pig pan became the clan Moua. Two pieces that landed in the garden turned into the clans Vang and Yang. This is how they founded all the Hmong clans."Source: Johnson, C. and S. Vang. (1992). Myths, Legends and Folktales from the Hmong of Laos //Dab Neeg Moog. Saint Paul , MN : Linguistics Department, Macalester University"

"My mother use to tell me a similar story about the naked man and woman who lived on the moon. The Hmong God (Sauj) told them not to eat the fruit from the tree. My mother would say that if you look at the moon, you can still see the tree and its branches, referring to the swirls and craters in the moon. One day the man and women ate the fruit from the tree and started to be aware of their nudity. They became shy and covered themselves with leaves. Later they developed feelings for each other and had a baby. When the baby was born, Sauj cursed them and the baby was born a lump of meat. The couple then sliced it up in many pieces and tossed it down to the earth. The next day, all the pieces turned into human beings and thus the different clans were created." Source: Anonymous.

Clans (Xeem)

Romanized Hmong	English
Tsab/Tsaab	Chang, Cha
Tswb	Chue, Chu
Tsheej	Cheng, Ching
Faj	Fang
Taag/Haam	Hang
Hawj	Her, Heu
Khaab	Kang, Kha
Koo	Kong
Kwm	Kue
Li	Ly, Lee, Li
Lauj	Lao, Lo, Lor
Muas/Zas	Moua, Mua
Phab	Pha
Thoj	Thao, Thor
Vaj	Vang, Wang, Va
Vwj	Vu, Vue
Xyooj	Xiong, Song
Yaj	Yang

Under Hmong custom, clans do not marry members of the same clan nor those belonging to certain other clans as determined by standing customs and kinship pacts.

A family consists of two common features: clan name and traditions. The clan name plays a vital role of adjusting and attributing values and beliefs within the family. It is particularly significant in the arts and language because this determines some differences in dialect and the oral poetry and/or folktales.

Hmong families that share clan names, but use different dialects, beliefs, and/or ceremonial practices, cannot be considered to be one family, but are of one clan.

Hmong last names are mostly clan surnames.  The majority of the surnames are monosyllabic, but some families have started using their paternal ancestors' first name as their last name and thus have introduced plurisyllabic surnames which will lead to new surnames and be will eventually lead its own clan or a new clan.  This is similar to Western suffixed joining two last names such as Van-Smith, and etc.