本論文旨在探討非營利組織及其捐贈者所享受的租稅優惠，是否應依組織性質的不同而有所差異。本研究參考相關文獻及美國內地稅法的分類方式，將國內非營利組織依公益性質及商業性質劃分為六類，並寄發問卷詢問國內會計師、營利事業財務主管及負責人、非營利組織管理者及負責人、學者及稅務人員對此六類組織及其捐贈者享受各項免稅優惠的贊同程度。本研究以敘述統計、t檢定及一般線性模式等統計分析方法對文獻探討所建立的假說進行測試，得出下列實證結果： 一、各界對於非營利組織及捐贈者享受免稅優惠的贊同程度，依組織公益性質的不同而有顯著的差異。公益程度愈高者，各界贊成免稅的程度愈高。 二、各界對於非營利組織及捐贈者享受免稅優惠的贊同程度，依組織商業性質的不同而有顯著的差異。各界對不具商業性質的組織有較高的免稅贊同度。 三、各界對於非營利組織及其捐贈者享受租稅減免優惠的贊同度，因減免項目的不同而有顯著的差異。 四、各界對於捐贈者享受所得稅或遺贈稅扣除優惠的贊同程度高於非營利組織本身享受各稅減免的贊同程度。 五、非營利組織管理者對於組織本身享受所得稅、營業稅、關稅及財產稅免稅優惠的贊同度顯著高於其他受試者。 經過文獻探討、各國免稅規定之比較及實證結果分析之後，本文重要的結論與建議如下： 一、鑒於公益性組織與互益性組織在所得稅上享受相同的租稅優惠，建議修改免稅適用標準，比照英美的做法將非營利組織依公益性質有系統的劃分為二至三類，並依組織公益性質的不同給予不同程度的租稅優惠。例如：對私人基金會的投資所得課徵特種稅(excise tax)；個人或企業對互益性組織的捐贈行為應享受較少的所得稅及遺產及贈與稅之免稅優惠。 二、建議恢復部分非營利組織銷售行為免稅的規定，可參酌英國、美國、新加坡及德國的稅法規定，將免稅範圍限制於符合免稅目的或慈善目的之銷售行為，或給予具商業性質的組織及其捐款者較低程度的免稅優惠。 / This study classifies the nonprofit organizations in Taiwan into six categories in terms of the degree of their public and business characteristics. The subjects are asked to express their opinion to the tax exemption of these six kinds of the nonprofit organizations. The subjects include the scholars, the certified public accountants, the managers and executive officers of the nonprofit organizations and the business companies, and the tax collectors of the tax authority. Descriptive statistics, t tests, and GLM are applied to analyze the responses of the subjects. The following results are obtained: 1. The subjects' agreement to the tax exemption of the nonprofit and its donators are significantly influenced by the degree of public for the organizations. The higher the degree of public for the organizations, the higher the subjects' agreement. 2. The subjects' agreement to the tax exemption of the nonprofit and its donators are significantly influenced by the degree of business for the organizations. The subjects have higher agreement to the tax exemption of the non-commercial organizations. 3. The subjects' agreement to the tax exemption of the nonprofit and its donators are significantly different between the different taxes. 4. The subjects' agreement to the tax deduction for donation is higher than the agreement to the tax exemption for NPO. 5. The managers of the nonprofit organizations have higher agreement to the tax exemption of the nonprofit than other subjects. After analyzing the responses of the subjects and comparing the tax laws of several countries, we provide following proposals to revise the tax laws. 1. The nonprofit need to be systematically classified according to the public characteristics and treated differently. For example, the investment income of the private foundations needs to be taxed for excise tax; donators of the mutual organizations should be benefited less by the deduction of the income tax and estate tax. 2. The tax exemption of the sales conduct of some nonprofit organizations should be retained but subjected to the organizations whose conduct conforms to the charitable or exempt purposes. Besides, the commercial organizations should be benefited less by the tax exemptions.