日文裡用來表現否定的方法大多使用否定助動詞「ない」「ず」等，不過也常見在漢語後添加「不」「無」「非」「未」等否定接頭詞的表現。又，日文的接頭詞一般只具有增加詞義的功能，但是漢語系統接頭詞裡表達否定意義的「不」「無」「非」「未」卻具有轉換品詞詞性的功能，如「無意識（な）」「不自由（な）」等。 本稿係以否定接頭詞「不」「無」「非」「未」為研究對象，主要目的在透過實際的調查研究，從型態、音聲、語義三方面陳述此四字在日文裡的表現；同時，釐清中日同形語之間的異同。 研究結果顯示，漢語系否定接頭詞「不」「無」「非」「未」除了和漢語結合之外，也和和語結合。不過現代日語裡，有出現「非」和外來語或混種語結合使用的現象。否定接頭詞具有改變結合語基之品詞詞性的功能，而「非」則常須在語尾添加接詞尾「的」才能使該語變成形容動詞。表否定之意的「不」「無」「非」「未」其主要的否定方式彼此之間仍有些許不同。此外，表否定之意的漢語系接頭詞有時也可做為對義語的造語詞素。

Although a negative auxiliary verb “ない” “ず”are used in many cases as a method of expressing negative in Japanese, attaching and expressing [many] negative prefixes, such as “不” “無” “非” “未”, to a Chinese word are also seen. Moreover, a Japanese prefix usually does not convert a part of speech only by making a word add a meaning. However, “不” “無” “非” “未” which express a negative meaning also in a Chinese word system prefix may convert a part of speech like “無意識(な)” and “不自由(な)”. By making the prefix “不” “無” “非” “未” showing negative applicable to research, after considering comparing respectively semantic form-[the word formation by “不” “無” “非” and “未”] sound character through actual investigation, this paper carries out contrast comparison of the isomorphism word from a function, or usage and a meaning further in the words of the same shape both in Japanese and Chinese, and specifies the difference or common points.