租稅規避案例中保險躉繳事件為經常出現之類型，財政部函釋雖揭示判斷要件，惟似無可依循之明確依據。本文藉由統整歸納2011～2016年之遺產稅保險躉繳案件判決，藉由類型化與體系化之分析，窺探實務判決引用法規依據、租稅法律主義、實質課稅原則、司法院釋字第四二○號、稅捐稽徵法與租稅規避之意義為論述基礎，再套入案例事實適用而得出結論。在現行法下，稽徵機關應就課稅事實認定為詳盡揭露之舉證而適用應課徵稅目，並督促立法積極行使立法權，進行立法防堵與預防租稅規避行為之發生。最後提出保險躉繳租稅規避行為之可能解決途徑，藉由參考日本法之免稅額設計，建議我國在保險躉繳事件，增設保險金免稅門檻之行為進行租稅規避之預防與防堵規避。

According to the judgment expressed by the Supreme Administrative Court, the cases of single premium business activity are often related to the tax avoidance categorization. This paper examines these single premium insurance cases and finds that the Supreme Administrative Court Judgments always use keywords such as tax regulations, Principle of Taxation by Law, The Principle of Substantive Taxation, J.Y. Interpretation No. 420, Tax Avoidance, etc. This paper firstly classifies the cases of single premium business activity to “Short Single Premium Life Insurance”, “Short Single Premium Investment Insurance”, “Lending Short Single Premium Mix of Life and Policy Loan Insurance” and “Short Single Premium mix of Life and Investment Insurance”. Secondly, this paper attempts to find the changes on the cases of single premium business activity of tax avoidance. Moreover, this paper argues that the Supreme Administrative Court Judgments should clarify on how facts, evidences, and principle of taxation by law are reviewed as it will enable taxpayers to understand the judgment. This paper makes a reference to the “gift and inheritance tax” system in Japan which designs the Amount of Tax Exemption on Life Insurance to reduce the risks of tax avoidance. Additionally, this paper suggests that the Legislative Yuan should amend the law to gradually reduce the tax avoidance activity.