對中國大陸及相關問題的研究，在面對中國大陸以政治、經濟與武力威脅，並不時主張對台擁有主權的台灣而言，實在很難脫離「顯學」的地位；也就是因為中國大陸的威脅一直存在著，兩岸關係與台灣的生存就不得不緊密結合在一起，所以對中國大陸問題的研究，以兩岸關係作為研究結果的呈現，就成為學者所熱中的項目之一。當前，兩岸關係的研究已到汗牛充棟的地步，但對兩岸關係理論的建立卻明顯不足，這個不足對於已有的兩岸關係研究成果，常構成諸多不周延之處，經常被學者提及。 現有兩岸關係的研究，雖有外交史途徑(the diplomatic history approach)、分裂國家途徑(the divided nation approach)、理性選擇途徑(the rational choice approach)、菁英衝突途徑(the elite conflict approach)及不對稱政治過程途徑(the asymmetrical political approach)等五大類，但卻沒有任何一類將台灣國家認同分作制度認同、文化認同及族群認同三個環節加以討論，並依此討論作為研究兩岸關係的途徑者，但明顯的卻是台灣的國家認同內涵變化，對於兩岸關係具有決定性的影響力，因此，本論文在假設中共對台「併吞」態度長期不變的情況下，集中探討台灣民眾由兩蔣時代經李登輝時代，到陳水扁時代的國家認同轉變，及其對兩岸的影響，並意圖建構以台灣國家認同變遷作為自變相，以兩岸關係作為應變相的兩岸關係研究途徑（approach），甚至進一步建立國家認同變遷對兩岸關係影響的理論，至少也應補充現有兩岸關係的各類理論，讓各家理論或研究途徑在解釋、描繪與預測兩岸關係過程中，多加考慮台灣民眾對國家認同的主流意向，使得兩岸關係的相關理論或途徑因而更加周延與完備。 「國家認同」（national Identity）的含意眾說紛紜，國內學者江宜樺教授主張國家認同應該以「族群認同」、「文化認同」及「制度認同」三個主要層面來討論，只有三個層面的綜合表現，才得以稱為完整的國家認同內涵，本文就是借用此三個環節，進行國家認同的討論，本文中更指：「族群認同」是以認同中國人或認同台灣人為討論主軸，「文化認同」則指台灣經由本土化的推動後，台灣人民對於台灣文化或中國傳統文化認同的區隔，「制度認同」是在討論台灣人民認同中華民國政治體制運作，或認同中華人民共和國政治體制運作的區別；由兩蔣時期、李登輝時期及陳水扁時期，台灣在此三個環節中的整體表現，構結出當時特有的國家認同表現，從中以縱向比較的方式，討論台灣國家認同的變遷情形，並就當時的國家認同情形與當時的兩岸關係作相對應的探討，以建立自兩蔣以降台灣國家認同變遷與兩岸關係變化的因果關係，再從因果關係的確立中，推論出現階段及往後兩岸關係，在台灣領導人有意引導國家認同變遷方向，及中共僵硬的對台政策相互衝撞下，兩岸關係的可能發展方向，提供在此領域的研究者另一種值得深思的面向與空間，讓兩岸關係的理論建構更加完備。 / Researches of Mainland China and relative inquires can hardly be separated from the position of “Explicit Learning” in Taiwan, while facing political, economical as well as military threats from Mainland China, in addition to the constant declaration of its sovereign right on Taiwan. Due to the threats from Mainland Chain remain unchanged, cross-strait relations and the existence of Taiwan can’t help but tightly link together. Thus, presentations of research results concerning cross-strait relations have become one of the popular research topics for scholars. At present, numerous researches of cross-strait relations have been carried out, yet the establishment of cross-strait relations theory is somehow obviously inadequate. Such insufficiency often results in a variety of negligence to the outcome of existed cross-strait relations researches and it is frequently brought up by scholars. Although present researches on cross-strait relations are categorized into five approaches; the diplomatic history approach, the divided nation approach, the rational choice approach, the elite conflict approach and the asymmetrical political approach. Nevertheless, there is none to categorize Taiwan national identity into three key aspects which are systematic identity, cultural identity and ethnic identity for further discussion, and nor is it discussed accordingly to include it as an approach of researching cross-strait relations. However, it is clearly that the connotation change of Taiwan’s national identity has decisive influence on cross-strait relations. As a result, this dissertation is based on the assumption that China’s attitude of swallowing up Taiwan by military force remains unchanged in the long run and concentrates on the discussion of national identity alteration of the Taiwan people starting from the era of Chiang Kai-Sheik and his son Chiang Ching-Kuo, via the era of Lee Teng-Hui to the era of Chen Shui-Bian , and its influence on Mainland China and Taiwan. It also means to build a research approach on cross-strait relations in this dissertation by setting the change of Taiwan‘s national identity as the independent variable and cross-strait relations as the dependent variable. It further establishes a theory of the influence of national identity alternation on cross-strait relations. Therefore, this dissertation at least provides additional information to assorted theories of cross-strait relations and allows scholars to take the main-stream national identity of the Taiwan People into deeper consideration while they are in the process of explaining, describing and predicting cross-strait relations; hence, it makes the related theories or approaches of cross-strait relations sounder and more complete. The meaning of national identity is rather confusing. Professor Chiang Yi-Hua thinks that national identity ought to be discussed from three aspects of ethnic identity, cultural identity and systematic identity. Without a combined performance of these three aspects complete national identity connotation can’t be existed. This research uses these three aspects to make discussions on national identity. In the research it clearly points out “national identity” is discussed mainly on identifying the Chinese or identifying Taiwan people and “cultural identity” means the identity division of the Taiwan people towards Taiwan culture or Chinese traditional culture after the movement of localization. “Systematic identity” is to discuss the identity difference of the Taiwan people in the political system operations of the Republic of China or People’s Republic of China. Taiwan’s overall performance of these three aspects, from the era of Chiang, Kai-Sheik and Chiang Ching-Kuo, via the era of Lee Teng-Hui to the era of Chen Shui-Bian, created a specific national identity performance during those periods. Vertical comparison was applied to discuss the change of Taiwan’s national identity. Mutual discussions on national identity and cross-strait relations during that period are also completed to launch cause-result connection between Taiwan’s national identity and change of cross-strait relations since the two Chiang era, afterwards, present and future cross-strait relations are inferred from the certainty of cause-result connection and possible development of cross-strait relations under the impacts of Taiwan leader who intends to induce the alternation direction of national identity and Mainland China’s stiff Taiwan policy. It is to present another thinking path and space to researchers who are involved in this field and allow the theory structure of cross-strait relations better equipped.