1930年伊藤永之介發表於日本的小說〈平地蕃人〉，繼承文協、農組、賴和以降的糖業批判論述，是第一篇有關台灣平地原住民族的小說。本文首先略述故事梗概，透過相似作品的比較，指出該作的衝突高峰和議題核心。包括它與第一篇台灣農民襲警故事－賴和〈一桿「稱仔」〉，及山部歌津子泰雅族巡查補故事《原住民賴薩》的互文性（intertextuality）。其次，探討作者如何以農民們的「說話體」，與「作者客觀補述」相輔相成，在多族群混雜的社會空間裡，展現出主人公的原住民自覺。第三，比較《臺灣日日新報》、《臺灣民報》、《臺灣大眾時報》和當時的糖業研究專書，辨析小說素材來源。最後，比較作者、官方及財閥的「東部開發使命論」之差異，說明伊藤為台灣平地原住民及日本農業移民代言的價值主張。

In 1930, Itō Einosuke published the novel "Flatland Aboriginals" in Japan, which inherited critical discourses on the sugar industry from the Taiwanese Cultural Association, Taiwan Farmers' Association, Lai Ho and others. It is the first novel that focuses on the plains indigenous people of Taiwan. This paper provides a brief overview of the story's synopsis and explores its key conflicts and thematic core through a comparison with similar works. Specifically, it examines the intertextuality between "Flatland Aboriginals" and the first Taiwanese farmer-assaulting police story, Lai Ho's "The ‘Steelyard,'" as well as Yamabe Katsuko's story about an Atayal assistant patrolman "Aboriginal Laisa." Next, it explores how the author complements the "speaker's voice" of the farmers with the "author's objective narration" to demonstrate the protagonist's indigenous self-awareness in the mixed social space of multiple ethnic groups. Fourth, this paper compares the sources of the novel's materials by analyzing the Taiwan Daily News, Taiwan Min Pao, Taiwan People Times, and books about the studies on the sugar industry at that time. Finally, the paper compares the differences between the author, the official and the zaibatsu's "theories on the mission to develop Eastern Taiwan" to explain Itō's advocacy for the value of representing Taiwan's plain indigenous people and Japanese agricultural immigrants.