華語由中國大陸引入台灣數十年後，因為政治上的阻隔、語言接觸的影響和語言實踐的結果，已經產生了顯著的變化。在發音、詞彙和語法等各個層面上，無論和引入台灣之前於中國大陸訂定的「標準國語」或是中國現行的「普通話」相比，都具有明顯的差異，語言學界將目前台灣通行的華語稱為「台灣華語」（Taiwan Mandarin） 「台灣華語」這一華語的變體是絕大多數台灣人日常生活時所採用的語言，作為華語中獨立的分支也是語言學界公認的事實，然而台灣的華語教學界鮮少將「台灣華語」的發音視為學習標的。華語教師教學時所使用的語言和台灣人民日常使用的語言存在顯著斷裂。 本研究檢視華語從一方之言到演變到「國語」的建構歷程以及華語在台灣的發展史，發現華語在台灣的發展和民族主義與國族認同的建構具有密切的關連。在回顧相關文獻與制度規章並佐以與現任華語教師的訪談結果後，發現台灣的對外華語教學界也普遍受到這種影響。教學的內容除了語言教學的專業考量外，尙存在著以往以獨尊華語、壓迫台灣其它語言的觀念及做法，認為「台灣華語」乃受「方言」污染而不純淨的語言，並以「華語」發源地的北京口音為嚮往對象。 最後，本研究從大眾傳媒的角度切入，探討「台灣華語」的最大公約數。認為「台灣華語」中許多成份已趨穩固，為絕大多數的台灣人所接受，也對全世界的華語人口具有相當的影響力。「台灣華語」的發音和繁體字、台灣式的辭彙與注音符號一樣應可視為「台灣華語」的重要成份，而能夠進入教學殿堂，作為外籍學生學習的對象。 / This study discusses the role of 'Taiwan Mandarin' in the field of teaching Mandarin as a second language. Results of the study indicate that Taiwan Mandarin is commonly disregarded, due to its association with other Taiwanese languages and the method in which it was introduced to the Taiwanese community. Decades after its introduction to Taiwan, Mandarin has evolved as a result of political and geographical separation from its origin in China, language contact, and local usage. This new variant, known as ‘Taiwan Mandarin’, has marked differences in terms of phonology, lexicon and syntax, and is viewed as a independent variant, different from ‘Guoyu’ or 'Putonghua' by many linguists. Although Taiwan Mandarin is, in practice, the most commonly used language by the Taiwanese people, it has been rejected by many language teachers and those who compile teaching materials for foreign learners. Language teachers are expected to teach an accent that is different from that of most Taiwan Mandarin speakers. This study investigates the standardization of modern Mandarin, and how it has developed in Taiwan. It shows that the enforcement of Chinese nationalism and identity is closely related to the popularaization of Mandarin in Taiwan. After reviewing related studies, regulation of teaching proficiency tests, and interviewing language teachers, it has been demonstrated that Chinese nationalism has also influenced the teaching of Mandarin as a second language in Taiwan. Taiwanese Mandarin phonology is commonly associated with the result contaminated by other Taiwanese languages such as Holo and Hakka by language teachers, and hence only the Beijing dialect is considered standard and desirable. Based on the findings of previous studies and interviews, this study suggests that the commonly accepted Taiwan Mandarin phonology can be gained through the language used in Taiwanese media, due to its steadiness and popular standing amongst Mandarin speakers world wide. Its unique phonology should be considered an important feature of Taiwan Mandarin, along with traditional characters, Taiwanese lexicon and phonetic symbols (注音符號), and it should be accepted in teaching methodology.