一般而言，國際法上的承認是一種自由與自願的單方行為。承認時常受到非法律層面的因素如經濟、戰略或其他複雜政治利益的嚴重影響。承認總是基於政策利益的主觀考量，呈現較少客觀公平的事實評估與審慎考量。相反地，不承認係指缺少承認、拒絕承認或不給予承認等情形。無論在承認的積極要件因任何一種理由而不存在的情形，不承認意指消極構成要件。不承認基本上可能是雙邊或集體多邊行為，包括一國對另一國的雙邊不承認(一對一)、或其他多國對一國的集體不承認(多對一)兩種行為態樣。不承認代表一種壓力與制裁。集體的不承認行為大部分係以非暴力性的制裁或杯葛形式出現，以及適用於處理各種國際非法行為的情勢。不承認的宗旨係要有效地阻止那些法律上無效的事物轉變為有效。誠如Hersch Lauterpacht教授 所言，就現今組織性不足、但守法的國際社會而言，集體不承認顯然是對於不法行為所能提供的最低度抵制，並且是一個針對法律上不法行為所能執行的持續性反對行為。故集體不承認得針對違反國際法的任何不法行為執行制裁與反對措施。最後本文將依循歷史與實踐分析法來探討國際法上集體不承認的淵源與發展背景，並且研究範圍上僅限以國際聯盟時期日本侵略中國的滿洲國事件為探索核心。

　　Recognition in general is a unilateral act with a free and voluntary nature. It is often affected by the non-legal reasons, for instance by considerations of political, economic, strategic interests. Thus, it is always appeared more on the ground of subjective policy interest of political nature that the objective and impartial assessment of exact facts. Conversely, non-recognition means the lack of recognition. It is the negative condition in the positive requirements of recognition and may not have one of these requirements for any reason. The mode of non-recognition may be bilateral or collective, and thus may appear sorts of one verse another one or one verse others. It represents a kind of pressure and sanction. The act of collective non-recognition in most cases is based on the form of nonviolent sanctions, and is applied to cope with various illegal acts in international law. Its aim is to effectively prevent a legally null and invalid act from being valid. As Professor Hersch Lauterpacht emphasized, it is the minimum of resistance that the insufficiently organized but law-abiding international community offers against illegality,and is a continuous challenge to these wrongs. Therefore, it shows a sanction and repression to these breaches of international law. Finally, this essay will discuss the origin and background of collective non-recognition in international law according to the methods of historical and philosophical analysis, and then in the research range, will focus on the Manchukuo incident that happened from Japanese invasion into China in the period of League of Nations.