在網際網路應用普及的推波助瀾下，全球經濟一體化已然成為時代之趨勢，造就了網際網路商業交易之盛行。基於電子商務交易之特性與傳統課稅觀念有著重大之差異性，除了對企業營運效率提升與交易成本之降低有助益外，企業更可利用網路無國界等特性，發展出新的逃漏稅方法，此將造成租稅稅基之流失。而我國電子商務交易量隨著時代的巨輪正加速成長中，電子商務之課稅問題，亦正逐一地浮現。 　　營業稅是我國的第二大稅，掌握營業稅當可掌握大部分所得稅之基源。本研究係從稅務稽核人員的角度切入，完整探討電子商務的運作內涵，進而瞭解電子商務因其特性所衍生課稅問題徵結之所在。依課稅管轄權、課稅觀念及稽徵技術等三個構面建立研究架構，嘗試在我國現行營業稅法規定下，檢討電子商務跨國線上傳送數位化商品及服務之適用性、衍生之稅收徵管（包含稅收損失之分析）問題，併歸納先進國家及國際組織之各種擬議文獻與實施經驗作為借鏡，據此結合國際共識與稽核實務提出具體建議，供政府因應電子商務發展而即將制定之租稅政策及修改營業稅制之參考，未來在不增加稅務行政成本及納稅人依從成本下，取得完整的交易稽核軌跡，防杜租稅逃漏，期能兼顧網路經濟發展及財政稅收之確保。 / After the rapid development of Internet and that with inciting e-commerce to be widely adopted by the most of business transaction, the Internet offers business opportunities to provide their products and services in a web-server without having a physical presence, which will erode tax revenue bases of a jurisdiction. The volume of E-commerce trade is accelerating in Taiwan. Many noticeable questions of taxing E-commerce will be seen in the near future. 　　Business tax is the second revenue of major taxes, collecting it could be holding the sources of income tax. From a view of a tax auditor, this research will explore the operation of E-commerce completely, and understand where the problem is generated by E-commerce. The framework of this study is composed of the taxing jurisdiction, taxing concept and collecting technique. Trying to test E-commerce transmitting digital goods and service on-line, and to test the adequacy of the existing laws and regulations on business tax are the major themes of this work. The suggestions of tax policy will be made according to the reference from the existing literature and the practice from advanced countries and international organizations. Considering the administration and compliance cost in the near future, how can we refrain from tax evasion and expect to increase tax revenue are all important to the development of economic activity through Internet.