以往有關網路交易的文獻，大多係對網路交易的課稅主張及稅捐徵免進行探討，甚少有在查核案例方面作著墨。本研究重視稽徵機關的觀點，探討我國自2005年制定「網路交易課徵營業稅及所得稅規範」後，稽徵機關對網路交易的查核原則及查核重點，並採質性及歸納研究法，以實務案例分析網路交易的各種違章類型。研究發現，如何維持實體通路與網路交易之間的租稅衡平，避免對蓬勃發展的網路交易造成衝擊，是相關行政部門需面對的重要議題；而網路交易業者更應從中釐清問題所在，思考合法的經營策略，以共創徵納雙贏。研究結論建議行政部門應從金流、物流及資訊流三管齊下，強化資料蒐集機制，並可透過機關間資源共享，進行交查，以收事半功倍之效；另建議網路交易業者應要求境外賣家詳實填寫進口貨物的交易價格，並於網站適度揭露公開資訊，以降低被查核及補稅處罰的風險。

Most studies about Internet transactions focus on taxation and tax exemption. This study emphasizes on tax authorities' auditing principles and points toward Internet transactions since enactment of ＂The Regulations for Levying of Business Tax and Income Tax on Transactions over the Internet＂ in 2005. Qualitative and induction methods are adopted in cases analysis for investigating violation types over Internet transactions. Results show the importance of keeping taxation balances between physical channels and Internet transactions for avoiding related impacts. Further, Internet traders should consider business strategies in legal transactions for creating win-win taxation situations. Conclusions suggest that administration departments should enhance data collection system in financial, logistic, information flow and reach the auditing effect by information sharing of each administration. Besides, Internet traders should ask foreign sellers to report accurately imported goods' transaction values and publish public information moderately over the Internet for reducing risks of taxations and overdue tax penalties.