對於臺灣土地改革形成之原因，一般是以「外因說」為解釋的主要理由，如外來國民黨政府的主導、及美國政府的協助等。本文主要是由歷史文獻之中，嘗試建構起「內因說」解釋的可能性，也就是要視土地改革是臺灣農村內部連續衝突過程之下所累積的結果，並假設土地改革的社會根源乃是來自於農村社會階級分化，及各階層民眾衝突的結果。由於農民最基本賴以維生的「生計倫理」遭到破壞，使得他們群起抗爭，致使國民黨政府不得不採行土地改革政策。本文所審視的土地改革政策包含「三七五減租」及「公地放領」，並不包括「耕者有其田」政策，最後發現「三七五減租」仍然是適用於「外因說」的解釋；但是「公地放領」則不然，它可能是比較適合於「內因說」的解釋。也由此得到兩個重要的觀點，那就是對於土地改革政策的研究可能要更細緻化，必須要將其分開來看待，這樣可能比較容易回復其歷史的原貌；另外則是以往因為土地改革的成功，而建構起來的「國權理論（state theory）」可能也要適度的加入民間社會抗爭的面向，政府的理性及能力是必須要放置於歷史的機遇中來對待，而不能獨立出來。

　　　　　The discourse on Taiwan's successful land reform usually puts effort on the actors of external forces – the KMT –state and U.S. aid. However, the objective of this research is to re-examine Taiwan's land reform experiences from the vantagepoint of its domestic social origins. The agrarian class relations and cultural construction in and after the Japanese colonial period might have had some specific influences on the initiation of land reform in post-war Taiwan. This research would like to investigate what types of tenancy relations existed? Did these relations promote or prevent the emergence of a deprived consciousness of the tenant classes? Were these relations changing over the course of the pre-land reform period? This research tries to answer the above questions, and a perspective using collective behavior and social movement theory is developed to analyze the land reform experiences in Taiwan.
The research investigates two major policies in Taiwan's land reform: one is "the 37.5% Farm Land Rent Reduction Program in 1949;" the other is "the Sales of Public Farm Land in 1948 and 1951." The results related to the above questions are very different. Much discontent from the domestic social origin toward landlords could not be confirmed in the case of the Farm Land Rent Reduction Program. Authoritarian control from the government and the horrific "228 event" taking place in 1947 all played important roles in preventing Taiwanese landlords' opposition to the Farm Land Rent Reduction Program.
However, the subsistence ethic seemingly had been violated in the other case. Many peasant movements emerged in 1947 and 1948, which were against the state-owned Taiwan Sugar Company. The authoritarian control used to justify the quiescence of landlords is not suitable to explain the emergence of those uprisings. This research maintains that those rebellions were the source for the policy of the sales of Public Farm Land in 1948 and the policies that followed. Therefore, the assumption of this research can probably be vindicated. This paper then argues that the experience of Taiwan's land reform should be much more carefully examined.