電子書為新興的交易客體，電子書線上交易也將成為未來知識傳遞之重要交易形態。本文從電子書之特徵和性質出發，對電子書之線上交易型態加以類型化，進而對電子書線上交易所可能涉及之法律關係加以剖析，特別是電子書提供者和讀者間之關係。此外，本文更進一步對於電子書線上交易契約之性質加以探討，分別就有償和無償契約和民法有名契約在特徵上是否有相近之處，加以比較分析，同時也注意到此種交易契約中，尚包含有著作權之授權關係或同意使用關係。最後本文對於電子書線上交易可能會產生之問題，包括契約成立、給付義務和債務不履行、電子書可能的物之瑕疵與權利瑕疵、瑕疵擔保責任，以及對於買受人使用約款上之限制，參酌國內外之學說見解，逐一加以分析研究，使讀者對於電子書線上交易可能產生之紛爭與處理有所了解。

E-book has become a new type of transaction objects. The transaction of e-books in internet will become one of important transactions related to transmissions of knowledge in the future. This thesis works on the character and nature of e-books. Followings, the types of e-book transaction and legal relations related to e-book transactions are dealt with, especially the relation between offer of e-books and reader. Besides, this thesis focuses on the nature of sale contract relating to e-book and comparing with other contracts in the Civil Code under the aspects of license of copy right and the right of use. Followings, it works on the obligations of e-book transaction in internet and comparing with legal opinions in other countries in order to describe some possible solutions of legal disputes which result from the e-book transactions in internet.