本文從認知的觀點探討韓戰爆發前後蘇中美三方究竟是如何認知對方，以及在認知過程中發生了哪些錯誤的認知。本文運用羅伯‧傑維斯（Robert Jervis）的認知理論（Cognitive Theory），即國際政治心理學的研究成果，來探討韓戰爆發前美蘇中三方的相互認知以及自己對各方認知的判斷，以解決在傳統韓戰研究中著重於政策制定過程中的盲點。 傑維斯提出的錯誤認知模式有：（一）將別人的行為視為集中統一的；（二）過高估算自身影響力或作為目標的重要性；（三）經常會進入一廂情願的認知陷阱（wishful thinking）；（四）認知失調理論（Cognitive Dissonance Theory），等四項。經過本文的論證之後，發現在此時期蘇中美三方或多或少都出現了錯誤認知。例如美國在判斷中共是否會參與韓戰時便犯了認知失調的錯誤，選擇性的相信收到的資訊，將與其所認知不同的資訊將之排除，因而造成了韓戰局勢的逆轉；中共從自身的觀點去認知美國，忽略了美國政界的複雜性，因為中共將美國視為集中統一的；蘇聯在韓戰問題上犯了一廂情願的錯誤認知，因為韓戰的成功對蘇聯的好處可說非常巨大，因此蘇聯忽略了包括美國態度在內的許多客觀因素。如果依照傑維斯所建議減少錯誤認知的方法來做的話，是否就代表可以避免錯誤認知？而因錯誤認知所產生的歷史事件是否可以避免？如同本文所分析的韓戰。本文發現似乎並非如此，而是韓戰有可能因為其他的正確認知或其他因素而依然發生。這便是傑維斯認知理論的侷限，在於忽略了歷史的連動性，把單一歷史事件從歷史的洪流中獨立出來解釋，使得理論的片面性被突顯出來。 最後，本研究從蘇中美三國在韓戰前後的互動為例，試圖經由歷史分析，探討錯誤認知是如何影響國家行為，隨著中共檔案的進一步解密，文獻分析研究仍有進步空間；此外，從理論研究美中蘇在韓戰的互動，認知理論結合建構主義與博弈理論，應該也是值得嘗試的理論途徑。 This thesis takes Robert Jervis’s Cognitive Theory which is the effort of international political psychology to figure out the triangle cognitions of China, U.S. and USSR during the war of Korea. And also discuss each diagnosis of others. Besides, it tries to solve the blind spots of traditional research of Korean war. There are four models which provoked by Robert Jervis. The first one is taking others behaviors as consolidation. The second one is highly valuated self influence or accounted itself as an important target. The third one is wishful thinking and the last one is Cognitive Dissonance Theory. Go through this thesis, we can find out that there are several mistakes of the triangle cognitions of China, U.S. and Russia during the war of Korea. The U.S., based on the wrong cognitive information which caused them failed in Korean war at the end of time. Furthermore, China analyzes U.S. from its point of view and neglects the complex situation of U.S. politics. It is because that China considers U.S. as an consolidate union. Russia makes the same mistakes as well. They believe that the success of Korean war could bring numerous benefits to themselves. They neglect the U.S. attitude toward the war and some objective factors. If we do believe in Robert Jervis’s Cognitive Theory, then it really means that we can avoid accept wrong cognitive information? And we do really can avoid some events which based on these wrong cognitions? From this thesis we can realize that the there are still exist other reasons and possibilities could caused the Korean war. The limited of Robert Jervis’s Cognitive Theory is to ignore the continuous factors of history. At last, this thesis takes the triangle interactions of China, U.S. and USSR during the war of Korea as an example and tries to go through by historical analysis to points out the wrong cognitions could influence national behaviors. By declassified some China’s documents, we know that there are a lot of improvements of documental research analysis. Furthermore, we also discover that combined with cognitive theory, constructive theory and game theory is a worthy research path for other researchers to give a try on it.