本論文針對冷戰結束以來的十六年間，美國政府對中共角色與關係之定位，欲探討的問題具體言之是「為什麼美國政府再一九八九年以來，對中共的關係定位會在『戰略夥伴』與『戰略對手』間發生擺盪」。本論文首先指出，理性主義雖是解釋國際關係時較慣用的工具，然而不論新現實主義、新自由制度主義均無法對此研究主題提供一套有系統的解釋；本論文繼而發現，建構主義雖承繼部分理性主義的決策模式概念，卻能對上述關係定位變動做出系統性的詮釋。 本論文共計六章：第一章通盤概述研究的動機、目的、方法，並闡明整個主題架構及限制條件。第二章勾勒出老布希、柯林頓、小布希政府對中共關係定位的變化，完成本論文的「描述分析」，作為整體論述之背景。第三章依循理性主義觀點，發現新現實主義無法解釋何以美國在「確保相對收益」的考量下會與中共採取合作；再者，按照新自由制度主義「開創絕對收益」的邏輯，卻與美國視中共為戰略對手，並陷入人權、貿易、台灣議題等爭議的情況不相符。第四章介紹建構主義的主要論點，並針對何以選定溫特的主流建構主義提出解釋，再逐一檢視建構主義的本體論、認識論、方法論、世界觀。第五章依循國際權力架構、理念等兩大參考點，驗證建構主義之解釋力。發現「亞太扇型戰略」、「多層次統一戰線」、「新保守主義」、「攻勢現實主義」等理念，是美國政府為美、「中」關係定位的重要因素。從世界觀的角度切入，如果是霍布斯的文化架構，中共會被美國視為「戰略對手」；如果是康德的文化架構，中共會被美國視為「戰略夥伴」；如果是洛克的文化架構，美國會在接觸中保持戒慎。第六章為結論，認為儘管建構主義提供一個較寬闊的解析平台，但建構主義與理性主義並非必然相斥，尋求兩個典範之整合，乃成為本研究針對後續研究所提出的建議事項之一。 / This thesis addresses an issue regarding the US Government’s identification of the Chinese role as well as the bilateral relations between the two states during the past sixteen years ever since the end of the Cold War. It deals specifically with the following question: why the US administrations since 1989 have shuttled their identification of China between a strategic partner and strategic competitor? It firstly argues that rationalism, as conventionally an explanatory tool in IR, proves insufficient to provide a set of consistent answer. Unsatisfied, this thesis continues its argument that the question brought forth at the beginning can be effectively resolved, or interpreted, by constructivism, despite the constructivist rationale may not necessarily render rational choice model utterly invalid in this case. Structurally speaking, Chapter One gives a brief with respect to the whole thematic structure inclusive of purpose of the study mentioned above and research limitations. Chapter Two demonstrates an effort of descriptive study as a set of background information by sketching out different phases of identification about relations with China that have been harbored by successive US administrations from President Bush Sr., Clinton to Bush Jr.. Chapter Three can be seen as an account of this thesis’ trying effort to explore the question per se from the rationalist perspective. The findings in Chapter Three are as follows: Neo-realism fails to explain why the US, premised upon concern of relative gains, would have cooperation with China. Neo-liberal institutionalism, following the logic of maximization of absolute gains, is inconsistent with an answer to the question of why the US would not given in on the issues of human rights and trade deficits. The above findings are suggestive. They open up the need for this thesis to observe the Sino-US diplomatic interactions from a social perspective in IR, i.e., constructivism. Chapter Four ushers in main points of constructivism. Two arguments are therefore in order. First, it gives a justification for the choice of the mainstream of constructivism in IR advanced by Alexander Wendt. Second, to suit the purpose of this research, it funnels the ontological, epistemological, methodological arguments, world views raised by the constructivist school and thrashes out two reference points—world power structure and ideation—for further observations. Chapter Five brings up the main body of the argument. It argues that a series of ideas such as A Fan-mode Strategic Concept in Asia Pacific, Multi-layer United Front, Neo-conservatism and Defensive Realism have been influential on the US identification of the relations with China. They in turn strike an image of Sino-US bilateral relations reflective of three kinds of culture distinguished by constructivists. In Hobbes’ terms, China can be seen as a strategic competitor. In Kant’s, China is a strategic partner. In Locke’s, the US is engaged but remains sceptical. Chapter Six is the concluding part. It goes beyond the phenomena and moves into the theoretical realm by arguing that, although constructivism offers a broader analytic platform, rationalism and constructivism need not be exclusive. That much room for integration of the two paradigms becomes one of the recommendations for further researches.