近年資訊傳播與內容創作之方法丕變，造成共同著作之數量與需求大增，判斷共同著作之存否及其歸屬，成為常見且重要之課題。我國雖於著作權法第8條當中設有共同著作定義之規定，惟立法、實務與學說未曾深論共同著作要件之判斷準則及其內涵，尤其共同著作人主觀之意思未經著作權法明文，學說或實務對於其作為共同著作要件之態度亦暗昧不明，若能就共同著作要件為檢視與釐清，不但有助共同著作存在與歸屬之判斷，亦可為共同著作與結合著作等相關立法提供修正方向。有鑒於此，本文擬透過立法與實務判決重新審視並且解構我國共同著作之要件，逐一觀察與分析其內涵，復藉由美國法之介紹與比較，發掘我國共同著作人貢獻部分、主觀意思以及資格限制等共同著作要件待審視或補充之議題，並且配合我國立法趨勢，檢討與評估共同著作人主觀意思、結合著作、以及共同著作特別規定等明文之可行性，進而提出立法建議，希冀作為未來相關立法與判決之參考。

Due to the rapid change of information dissemination and content creation, the amount of joint works has substantially increased in recent years. To identify and determine a joint work has become a crucial issue nowadays. Lawmakers, judges or scholars in Taiwan have seldom or never canvassed the standards and the connotations of the prerequisites of a joint work even if the Article 8 of the Taiwanese Copyright Law roughly provides the definition of joint work. The intent of the joint author which has not categorically written in the Article 8, as a perquisite of joint works, has especially been ignored by scholars and courts. To examine and clarify the prerequisites of joint works, however, will not only assist the determination of the existence and the ascription of a joint work, but provide the legislative guideline for future amendments on joint works and compound works. With this in mind, this article will thoroughly reexamine and analyze the existing prerequisites of joint works in Taiwan via the related legislation and cases; then explore the issues on the contributions, intents, and statutory limitations of joint authors by a comparative study of Taiwanese and the U.S. copyright law. Further, this article will review and evaluate the possibility of a copyright law amendment for expressly adding the joint author's intent in the Article 8, the codification of compound works, and the special provisions to limit the authorship of audiovisual works. Hopefully the finding of this article will become a useful reference for future legislation, and spark further concern and discussions about the related issues.