20世纪20-40年代，是中国近代民族国家建设进程的重要时期，西南地区由传统王朝的边陲之地一跃成为抗战救国的大后方，学界对西南少数民族的身份认知也经历从模糊到逐渐清晰的过程。本文以“学界”整体为研究视角，探究在民族国家建构与中西学术对话的背景下，学者如何通过撰述中国民族史和开展民族调查两种途径对西南少数民族进行身份建构，揭示其过程中所呈现出的认知分歧与共同取向。 在民初五族共和为主体的国家政治格局中，西南少数民族的族群身份一直未获得官方确认。近代中国民族史撰述突破了传统的华夷观念，将西南少数民族纳入到中华民族形成发展的历史框架中来书写。怀有“种族”概念的民族史作者，通过追溯西南少数民族的历史源流阐明了他们与汉族有千丝万缕的联系，为凝聚西南少数民族对中华民族的认同提供了重要的历史依据。然而，以汉族为主体的书写视角使得其文化的独特价值仍被置于过去文明与野蛮的二元评价体系中，难以彰显。 随着边疆危机的加剧和全面抗战的爆发，西南凸显其独特的战略地位作用， 关注西南、了解西南、塑造西南少数民族对中华民族国家的认同成为学界的首要学术使命。避乱西南的大批学者结合传统文献与民族调查，对复杂的西南族群身份展开多维方式的建构：搜寻历史与现实的证据以论证“夷汉同源”，建构本土化的分类体系来强调西南少数民族的边界与国家的边界的重合，重新估定西南少数民族文化价值，并将其视为中华文化的渊源与重要组成部分。通过民族史的脉络勾勒与民族调查的深入开展，西南少数民族的真实面貌逐渐清晰起来。 顾颉刚提出“中华民族是一个”的论题与暹罗更改国名引起的西南边疆危机感有关。围绕“中华民族是一个”而展开的论辩集中反映了不同学者对西南少数民族身份的认知分歧。学者的观点无论是“否认”还是“承认”西南少数民族的“民族”身份，都旨在将其纳入到中华民族国家的现代化建设进程中，只是思考问题的角度不同。学界尽管有不同的声音，但在抗战紧迫、民族危亡的紧要时刻，“中华民族是一个”的观点反映了抗战时期时代思潮的强势流向和国人的情感归趋。强调中华民族的一体性和整体性也成为政学两界的共同取向。 学界对西南少数民族的身份建构过程其实也是各学科交叉合力建构其历史知识与民族知识体系的过程。在中西学术对话的文化场景中，学者们一方面追求科学求真、严谨求实的学术理念，一方面在对国家和民族前途的热切关照基础上开展研究，彰显了学术思想与民族、国家利益的一致。学界对塑造西南少数民族身份认同所作的努力和尝试，不仅从学术上推动了中国民族史、人类学、民族学等学科的发展，而且起到了强化西南少数民族中华民族意识和国家观念的作用，同时从一个侧面揭示了从传统华夷观念到现代中华民族一体观念的转变过程。以“西南少数民族身份问题”为聚焦回溯历史，探究学者的学术活动，有助于加深对民国学术及相关学科整体发展特点的认识，从新的角度理解“中华民族多元一体格局”的丰富内涵。

It is an important period for the construction of a nation-state in modern China from 1920s to 1940s. The southwest region changed its geographical significance from the border area in the traditional dynasty to the rear area in the Anti-Japanese War. The academia's understanding of the southwest ethnic minorities changed as well, from vague to gradually clear. Based on the perspective of the academia, this study explores how the scholars constructed the identity of the southwest ethnic minorities and what their cognitive differences and common orientations are in the context of the nation-state construction and the academic dialogue between China and Western countries. The ethnic minorities in the southwest was not officially recognized in the political structure where “Five Nationalities” was the main body in the early Republic of China. At that time, Chinese ethnic history has broken the old concept in ancient China and brought the southwest minorities into the historical framework of the formation and development of the Chinese nation. The author clarified the inextricable links with the Han nationality by tracing the historical origins of the ethnic minorities, which provided an important historical basis for the identification of the ethnic minorities in the southwest. However, the writing perspective centered on the Han nationality makes its unique value of culture still be placed in the opposition evaluation system of past civilization and barbarism. It’s hard to be revealed. With the intensification of the border crisis and the outbreak of the Anti-Japanese War, The southwest acted its unique strategic role. Paying close attention to the southwest and shaping the minority's recognition of the Chinese nation became the primary academic mission. A large number of scholars who entered the southwest combined the historical documents and ethnic investigation to construct the complicated southwest ethnic identity by a multi-dimensional way. They searched for historical and realistic evidence to demonstrate the ethnic minorities are homologous with the Han nationality, then constructed a local classification system to emphasize the coincidence of the border between the southwest minority and the state. In addition, they reassessed the cultural value of the ethnic minorities in the southwest and regarded it as the origin and important component of the Chinese culture. With the great efforts of the scholars, the true appearance of ethnic minorities in Southwest China become gradually clear. Jiegang Gu's proposition that “the oneness of Chinese nation” was related to the southwest border crisis caused by Siam's change of name. The debate about the “the oneness of Chinese nation” reflected the different scholars' cognitive differences on the identity of the southwest minority. Scholars' views thinking from different perspectives, whether "denying" or "recognizing" the "national" identity of the ethnic minorities in Southwest China, were all aimed at bringing it into the process of the modernization of the Chinese nation-state. Although there were different voices, “the oneness of Chinese nation” view reflected the strong trend of thought and the emotional trend of the Chinese people at the most dangerous time of the nation. Finally, emphasizing the entirety and oneness of the Chinese nation became the common orientation of the political and academic circles. The process of identity construction of ethnic minorities in southwest China was actually the process of interdisciplinary efforts to construct their historical knowledge and national knowledge system. In the context of the academic dialogues between China and Western countries, on the one hand, scholars pursued the scientific philosophy of seeking truth, rigorous and realistic. On the other hand, their research showed the consistency of academic thought and national interests. Scholars’ efforts not only promoted the development of Chinese ethnic history, anthropology, ethnology and other disciplines, but also played an important role in strengthening the consciousness of the Chinese nation and the national concept of the ethnic minorities in the southwest. At the same time, it reveals the transformation process from the old concept in ancient China to the modern concept of the Chinese nation. In a word, through analyzing the academic activities of identity construction of ethnic minorities in southwest China, it is beneficial to understand the overall characteristics of the academic development of the Republic of China, and the rich connotation of the "pluralistic integration of the Chinese nation" from a new perspective.