本文探用人類學族群研究觀點，透過認識高屏地區客裔相對強化之姻親連帶，及獨特之母方父系祖堂敬拜婚俗，思考六堆社群界限（boundary）的性質。其中，美濃是右堆的中心，又是六堆的北端邊緣，其所累積的民族誌提供我們理解上述議題的一個起點。在概念上，地圖過去提供了人們理解六堆界域的型態，卻某種程度上建構各界對六堆乃一有著固定疆域或族群邊界的印象。本文提出六堆界域並非一單向對外產生抵禦或封閉的歷史狀態，在地圖上的界線，應視為一種族群認同的實踐界限。在該界限上，人們經由語言、祖先崇拜、姻親關係、物產交換等衝突與交融，產生不同的日常生活文化會遇，交疊出這一條帶著我群與他群的內／外意識分野。本文認為，六堆組織在二十世紀初解散前所擴張、緊集、捍衛之生存區域，是客裔社群在生存適應底下的聰明選擇，不僅展現其對判讀農業資源地下水的豐沛知識，亦有著明顯對探取姻親締結範團及對象的選擇性偏好，最終在物質與認知層面，共構這條並不真實存在於地圖上的界限。另一方面，這條帶有族群邊界味道的界限，正因其非真實存在，從許多蛛絲馬跡中也可看到其在穿透性上的特質。

From an anthropological perspective on ethnic studies, this paper intends to explore the nature of the community boundary of Liudui, by understanding the reinforced marital relationship of the Hakka descendants in the Kaohsiung and Pingtung areas, and their unique marital custom of visiting the shrine of the mother's side's family. Meinong, the center of Yodui and the northern border of Liudui, provides important local records and materials to research this issue. In theory, people know the Liudui area and its location through a map. This, however, creates an impression of Liudui as a place of a certain ethnic group with fixed borders. From an anthropological perspective, this study argues that the Liudui area was not formed through a one-way defensive purpose or a closed history; the line drawn on a map should be seen as a boundary for practicing ethnic identification. People obtain awareness of the inside and outside of that boundary, as well as of the local people and others, through different daily social and cultural encounters in terms of languages, ancestral worship, marital relationship, trade and conflicts. From the researcher's viewpoint, the living area of Liudui that was expanded, consolidated and protected before it dissolved in the beginning of the 20th century reflected correct decisions for the survival of the Hakka communities. It not only demonstrates the rich knowledge of agricultural resources, but also shows the preference of a certain culture and customs, finally forming this boundary that cannot be found on a map in regard to material dimensions and recognition. Moreover, this ethnic boundary can be found in many small traces of daily life due to its non-materialistic existence.