探討公法與私法之區分，早已於法學領域歷久不衰，其中民法與稅法之分合史，即一適例。本文所針對「被繼承人稅捐債務可否成為繼承標的」之相關問題亦同；除最高行政法院於二○○三至二○○四年間，以兩次決議之篇幅予以討論並統一見解，對其關切程度可知外；更因此涉及繼承法與遺產贈與稅法在法理上之交錯適用，而在稅法學上有釐清必要。本文總括地認為，此問題主要涉及公私法債權債務所適用法理不同，而在概念解釋上與法規適用上應有所區隔之故。本文乃從總遺產稅制觀點，認為遺產稅與贈與稅二者本具互補關係，其正當性不僅為憲法所保障，且因而具體賦予被繼承人透過生前贈與方式以降低遺產稅率之規劃自由。遺贈稅法第十五條第一項之規定，毋寧宣示一租稅規劃之可能性與界限，惟其針對逾越租稅規劃界限之防杜上，透過「擬制」之手段，賦予原為稽徵機關之舉證責任因而轉由繼承人承擔之效果；不僅未考量被繼承人生前二年內之租稅規劃自由，更因其無從預期稽徵機關對該贈與行為構成要件事實之判斷（如遺贈稅法第五條視同贈與之規定，亦為第十五條擬制遺產之對象）而不具有規劃之可能，實有修正必要。另外，憲法在肯認人民財產自由權之同時，即已確保其租稅規劃之可能性；而此亦稅法係依附於私法之必然解釋。此依附之效力，當尊重財產權人在私法上之財產安排為優先，僅於顯有逃稅避稅之虞時，因其信賴不值得保護而始有介入之可能；其介入手段係按常規交易調整，其介入範圍則以財產權所附之社會義務為限。

The debate over the distinction between Public law and Private law has been playing one of the leading characters in the academic arena of jurisprudence, among which a representing example would be the history in the separation and integration of civil law and tax law. The main issue drawn upon in this article-whether tax liability is transferable through inheritance-is another example in similar nature. The importance of this issue can not be emphasized more not only for the fact that, in response to the great judicial concerns, two resolutions have been made in the liaison meeting of the presiding judges and the judges held by the Supreme Administrative Court during the year 2003- 2004,but also the issue itself intrigues cross-application of legal theories academic efforts to entangle the situation. Briefly speaking, this paper intends to conclude that the reason can be boiled down to the fact that the distinction in theories of liability between private and public law should be clarified both in the sense of application of law and of interpretation of related concepts therein. From the perspective of the estate tax system in contrast with the inheritance tax system, not only does there exist an interrelationship between estate tax and gift tax, of which the legitimacy are guaranteed by the Constitution, but as well the Constitution renders justification of a person the freedom of the arrangement of his property in the sense of tax planning by means of gifting his successors-to-be in order to reduce the high death tax rate. Under article 15, paragraph 1 of the Estate and Gift Taxation Law(EGT), it is understood that the law reveals a possibility as well as a limitation to tax planning; however, in terms of its mechanism of anti-tax-evasion, the legislative approach which transfers the burden of proof from the side of tax administration office to taxpayers' side has already infringed upon a person's rights over property before his death, protected by the Constitution; what's more, this certain legislation also infringes the authority of tax administrator by setting specific type to the definition of ＂gifting＂ regardless of the discretion of administration office; thus, it is imperative that the article be in need of modification. In addition, as soon as the Constitution confirms people of his rights over property, it guarantees the possibility of rights of taxplanning; therefore, reflecting the fact that tax law is bound to be subsidiary to private law. The ＂subsidiary＂ effectiveness refers to the prioritization of the arrangement of private property in terms of private law. Only when there exists conspicuous signs of tax avoidance will there be legitimate grounds for legal interference of one's property arrangement in regard to his certain arrangement is no longer legally credible. However, the action taken for the interference is the modification of the tax burden which is in accordance with normal dealings, and the scope of the interference is limited to the portion of the social obligation of the property rights.