觀察近年來的行政訴訟類型，乃是以稅務訴訟占大宗，以2005年1月1日至2011年2月底最高行政法院之判決為例，在所作成之29006則判決中，其中與稅相關之訴訟即有11581則。而本文即以2005年以後至2011年2月底為主，與稅法有關之行政法院判決、大法官解釋以及要求明確化所引發之相關稅法之修正，擇定以下幾個議題作為說明分析之範圍：脫法避稅與實質課稅、協力義務與推計課稅、退稅請求權（稅捐稽徵法第28條）、租稅違章案件之裁罰（裁罰參考表）。又法院判決與其時學說發展密不可分，尤以我國繼受德國法制，如脫逸此種背景，難以充分理解。在我國，稅務訴訟案件之數量與比例之所以居高不下，除了人民權利保護意識之抬頭外；在稅務爭訟上，稅捐稽徵機關所執作為課稅依據之解釋令函，經常成為納稅義務人所爭執之對象，此種現象之發生可能來自於徵納雙方對於稅法規定之理解有所不同，以至於財政部所作成之解釋令函在執行上造成納稅義務人難以遵從，以致於發生爭訟之情事，而這也是導致稅務訴訟數量居高不下之原因。此外，租稅行政罰，處罰過當，無罪推定等法治概念，未能深入基層稽徵機關，亦為可能原因。在行政訴訟改制十年中，長年占行政訴訟半數之稅務訴訟，雖然人民勝訴比例仍不高 ，但判決品質十年來有相當進展，值得吾人重視。而一個突破性判決，帶動稽徵機關法治觀念之變遷，絕不下於立法之改革。

Ranging from January 1, 2005 to February 28, 2011, the number of tax litigations amounted to 11581 cases out of 29006, accounting for the bulk amount of administrative litigations. Focusing on the said period of time, this paper analyzes relevant cases, judicial interpretations as well as revisions in legislation, specifically in the issues regarding tax avoidance and substantive taxation, cooperative obligation and tax estimation, right to tax return (Article 28 of Tax Collection Act), and tax penalties. The soaring volume and ratio in tax litigations is a result of both the taxpayer’s self-awareness of their rights and the rulings made by the tax agencies seemingly unconvincing to taxpayers. Moreover, the excessive use of tax administrative penalties and lack of ideas such as the presumption of innocence in the tax administrations could also be the reasons. In the decade after the reform of Administrative Procedure Act, given the fact that the winning rate of taxpayers are still low, the quality of the decisions makes evident progress. A breakthrough decision, often incurring the change of ideas in the tax administration, is no less important than a legislative reform.