The differences in inhabited areas and other factors in process of social development form the regional dialects, sub-dialects and the trappings of Yi. These Yi groups of that speak different dialects or sub-dialects have obvious regional characters. Yi People is a ethnic group that has multifarious sub-groups and self-appellations.

Liangshan Yi's finery Photo by Tang Hu

　　Yi Language mainly consists of six dialects, namely dialects of northern, eastern, southern, southeastern, western and middle. Each dialect has many sub-dialects and vernaculars. The dialects are so different that people speaking different dialects can not communicate or understand each other. There are more than thirty types of Yi dress. The types of dress, the dialects and the self-appellations are important references by which we differentiate the sub-groups of Yi People.

　　'Ni' is the earliest and uniform self-appellation of Yi People. According to Brief History of Yi , there are 35 self-appellations and 44 other-appellations to the Yi people. However, it is only a small part of the complicated self-appellation system of Yi. In fact, there are more than one hundred self-appellations in the history of Yi, such as Nosu, Niesu, Nasu, Lo'ao, Axipo, Sani, Azhe, Awu, Alu, Lolo, Ado, Lomi, Taliu, Lawusu, Misapo, Gepo, Samodu, Naro, Nazhasu, Talusu, Shansu, Nalopo, Lipo, Lalupo, Luxunbo，Misapo, Azubo etc.. After the foundation of the People's Republic of China, these people are officially named Yi at their will.

Shilin Yi's finery

　　The number of Yi People that call themselves Nosupo, Nasupo, Niesupo(or Nisupo), Nipo and Sanipo accounts for more than half of the whole population of Yi distributed in Sichuan, Guizhou, Yunnan and Guangxi provinces. According to the dialects, these self-appellations are all distributed in region of eastern dialect, northern dialect, southern dialect and southeastern dialect. The Yi people that call themselves Lopo, Lolo, Nalo, Lalo and Lupo all belong to the Middle dialect and Weatern dialect. The number of this part of Yi accounts for 20％ of the whole population around and their self-appellation has relationship with totem of dragon and tiger. In addition, Lopo, Lo, Li or Le which are in the same tone, are in fact the same self-appellation in different speech of vernacular. It means "mountain" and "field or outside", namely "the folk living in mountains". The speeches and conventions of these Yi are comparatively close to those of Lolopo Yi. Both Nipo and Lipo are willing to accept Yi as their self-appellation. The complex self-appellations can be summarized as 'Yitong Sanda': Ni is the original uniform self-appellation with a long history, and Sanda means 'Three sub-system of self-appellation', namely the 'Nipo System', 'Lopo System' and 'Lipo System'. These three main self-appellation systems make a complicated system which derived from the original uniform self-appellation of 'ni'.

Distribution of Yi P Main Subgroups

　　From the view of culture and history , many reasons will be found why Yi people have so many different sub-groups and self-appellations. The formation of different self-appellations have relationships not only with factors, such as the tribe conflict inside or outside, which formed during the process of formation and multiplying of Yi, ethnic migration, social hierarchy, ethnic merging and animism and worship of totem etc., but also mainly with the convention of grand ancestor worship in their celebration, named 'Naimu' in Yi, which existed from old times to now.

Luquan Yi's finery Photo by Zhang Bingting

　　Yi People adore its ancestry very deeply. The rite of ancestor worship(Naimu) is the embodiment or epitome by which Yi apotheosizes its ancestry, and it is regarded as the most important part of branch religion activity, and it is an important brace and link of Yi's highest grade for sacred proprieties and clannish religion activity. The view of this religion believes that ancesters are the protectors of their offspring who can decide their fortune and misfortune, that going back to the Ancestor World and reuniting with them after their death is their greatest wish, the Ancestor World is the finest Elysium in the world, and that whether the rite is well arranged is very important to both the living and the dead, and more important to the dead. In Yi society, the grand ancestor worship rite, or Naimu, is the greatest collective sacred proprieties to the ancestors shared by all of clans in the form of genealogical unit.

　　Yi celebrates collective sacred proprieties "Naimu"（耐姆） not only for recalling the ancestors' outstanding achievements, atoneing all kinds of offence for the ancestors and releasing their souls from purgatory to multiply more descendants, but also especially for knowing clan branches, recording and tracing the genealogy. To some extent, the history of Yi is the history of sacred ceremony and worship of ancestors

Photo by Zhong Shimin

　　Ximuzhe is acknowledged as the first paternal ancestor of Yi. From the time of Mudu, the 31th generation descendant of Ximuzhe(paternal lineage), the people of Yi began to record their genealogy in the form of naming after fathers. According to the Yi historical records, in the time of paternal clan society, three great Naimus or sacred proprieties were held (the first and second were before "the flood period", the third was after "the flood period"). The first was in the period of Daomengni, the 14th generation descendant of the first ancestor. It said that Daomengni had nine younger brothers and eight elder brothers who were allocated respectively to all places in Yi district to explore and develop, then became other branches or peoples of Yi language branch. The second great rite was in the time of Wuluocuo, Ximuzhe's 29th generation descendant. Wuluocuo had 12 brothers. The eleven elders crossed Dadu River and became the independent clans that respectively accepted tiger, lion, bear, monkey, snake, python, horse, tree, bee and chook as their totems (that is "the twelve branches of Wuluocuo" recorded in le'eteyi(勒俄特依), a literature classic in Liangshan district), and only Wuluocuo remained unchanged. The third Naimu was conducted in the time of Mumu, the 31st generation descendant of first ancestor, the time after the Great Flood. Mudu had 6 sons and later they became independent clans(that is known as "the Separation of Six Ancestors " in Yi recorded documents), i.e. Muaqie, the eldest(or Wu clan) and Muaku, the second(or Zha clan) moved southward; Muare, the third(or Nuo clan) and Muare, the fouth(or Heng clan) migrated to the north of Leibo district in Sichuan province; Muake, the fifth(or Bu clan) and the youngest extended to the areas along Jinsha River. After those three great Naimus, each clan became much stronger. Afterward, among the six clans Wu and Zha separated into lots of clans and sub-clans; so did Nuo and Heng, by this time those clans had developed about five hundred family clans; Bu and Mo also divided into about ten clan kingdoms named "Gou" in North-east of Yunnan province and North-west of Guizhou province. The descendants of "Gou" clans who, later, became the ancestors of Debudeshixing, a sub-clan mentioned above, spread all over the areas of Guizhou and Yunnan Yi people inhabit today. The American autochthon Indian often names their clans after animals, plants or nonliving objects, but Yi is different from Indian. Yi people frequently name their clans after names of typical ancestors during the Naimu period, self-naming gradually became the names of branches. The clans which are constituted of "Gou"（勾） developed into lots of sub-clans just in Luquan County of Yunnan; the black Yi branch,who named themselves as Nasupo, divided into about ten clans and sub-clan branches, among hundreds of branches, clans each branch celebrated the grand rite of ancestor worship(Naimu) every time, there always appears new names of clans each branch in Naimu. With development of clans and the going of time, self-reference or sub-self-reference, as their owners, became the symbolic title of the locations which they inhabit.

　　Because of special social and cultural conventions in the long history of Yi, different Yi branches formed various dialects or vernaculars, and different self-name bring us different clan place names. If different self-names bring different clan place names, then Naimu and other rites of ancestor worship may be the main reasons for the variety in Yi branches, self-names and dialects or local speeches.