爾蘇人是四川省甘洛縣和越西縣境內的一個少數民族群體。在1980年代，部 分爾蘇菁英份子聯名向中國政府反映，要求確認其群體爲一個單一的民族——「爾蘇族」丨1同時，另一些族人卻堅持爾蘇人應該屬於藏族。於是在爾蘇人中間出現 了兩派：一派自我認同爲爾蘇族，另一派則認同於藏族。「爾蘇族派」希望被識別 爲一個單一民族，而「藏族派」認爲爾蘇人是藏族的一個分支。本文介紹了當時 爾蘇人族群認同的分歧情況，並探討他們如何選擇與建構其族群認同。硏究顯示， 「國家」在爾蘇人的族群認同上扮演著重要的角色。爲了獲得政治上和經濟上的利 益，兩派爾蘇人一方面各自理性地表達了不同的族群認同；另一方面又都承認他 們同屬於一個「布爾日一爾蘇」群體。前者可以用理性選擇理論來理解，後者可 以從族群內心情感的立場去解釋。本文透過爾蘇人的民族誌記錄，揭示國家政策 與族群的形成過程。而在使用理性選擇理論來解釋中國少數民族的族群抉擇問題 的同時，亦展現了文化特徵或族群內心情感在族群認同表述方面的重要性。

This paper focuses on the construction of ethnic identities among the Ersu people, one of the minority groups of Ganluo and Yuexi counties in Sichuan province. In the 1980s, some Ersu intellectuals made a request to the Chinese state for the Ersu to be recognized as an autonomous minzu 民族 —Ersuzu 爾蘇族 or Ersu nationality. Meanwhile, some other members of the group insisted on being recognized as Zang 藏，or Tibetan, nationality. That means there are two main factions among the Ersu: one faction wishes to identify themselves as Ersu and another faction prefer to be Zang or Tibetan. The Ersu faction wants to be classified as an autonomous minzu, while the Zang faction wants to identify themselves as a Tibetan sub-group. This paper examines the diverse views on choosing ethnic identities among Ersu people. It discusses how they choose and construct their ethnic identities. It also shows that the state plays a crucial role in the people's identity politics. Seeking the best economic and political advantages, as well as a better position in relations of power, Ersu people choose their ethnic identities rationally in diverse ways. At the same time, both factions agree that they belong to same group—Perzii-Ersu (布爾日一爾蘇）group, which can be understood as a Primordialis identity. This paper contributes to the ethnography of the Ersu as well as an understanding of state policy and eth-nogenesis. It shows the relevance of rational choice theory in understanding choice of identity among an ethnic minority in China. It also shows the importance of cultural features or Primordialism in identity expression.