本文分六章，約十餘萬言。第一章為緒論，說明本文研究動機、目的、內容、方法與步驟。我國土地增值稅制，素來有累進與比例之爭，及倍數累進與金額累進之辯’惟雙方所持理由，並無明確的數據及嚴謹的學理。本文旨在探討現行土地增值稅稅制之缺失，比較倍數累進與金額累進之優劣，試擬改進之策略，俾使土地增值稅更能合乎課稅的公平與效率原則。 第二章為土地增值稅之理論基礎及文獻回顧。本章計分土地增值稅的理論基礎，稅基之涵義與稅率結構之類型，土地增值稅的課稅原則、轉嫁與歸宿，實現基礎與應計基礎之比較，長短期土地持有及投資與投機之界定等課題予以說明。 第三章為我國土地增值稅稅制之沿革及評述。首先將民國43年制定實施條例及施行細則以來的稅制變革分為六個階段，編製成六張表。表格內容分別按「適用時間」、「計算式」、「法條說明」及「備註欄」等項目說明。並再根據各階段的計算式，畫成函數圖形，以收清晰醒目之效。本章擬分土地增值稅立法之演進，我國土地增值稅稅基、稅率及稅額之分析，土地增值稅與個人綜合所得稅之比較，倍數累進與金額累進之比較等課題予以說明。第四章係實證分析。研究範圍為台北市，樣本數計二萬一千多筆，時間從民國56至74年。經由電腦程式除錯及統計檢定結果，資料可信度甚佳。實證分析結果為第一階段（43年8月一53年2月）稅率結構的稅收最多，漲價歸公效果最佳。若將台北市分為新、舊市區，採取倍數累進課稅，新市區的平均稅率大於舊市區的平均稅率，將來若按修正草案的金額累進課稅,新市區的稅率，反而小於舊市區。本章亦求解土地市場供需聯立方程式，結果顯示所得的需求彈性（3.9443）大於價格的需求彈性（3.2595），價格的供給彈性為 0.2573，此種情形反映土地增值稅的確有轉嫁的現象、本章最後以因素分析與迴歸分析，說明地價變動的主要因素源自於國家經濟的快速成長，政府公共建設支出的增長及人口的增加。故在合乎課稅公平與效率的原則下，土地自然增值歸公不容置疑，理當貫徹實施。第五章是從系統動態學的觀點，分析土地增值稅的長期變化情形，從漲價歸公的觀點，亦得證實模式4-9-1既能放進現行倍數累進制之缺點，亦能避免金額累進稅制下訂定級距之困擾。第六章、結論與建議。從本文研究分析結果，得知倍數累進的確優於金額累進。唯現行倍數累進課稅方式，級距太粗略，稅率遞增率太大，若能將漲價倍數以每1/2倍為一級距，稅率遞增率亦自現行的10％降為5％，則更能符合公平與效率的課稅原則。至於稅率100％的增值率，有礙土地流動性，降低土地利用，並不足取。關鍵詞：倍數累進，金額累進，倍數級距，邊際稅率，漲價歸公。 / This thesis consists of six chapters.Chapter l is the introduction,specifying the motive,objective, contents,methods and procedure of this research.Regarding the land value increment tax(LVIT),controversy has been held between the multipe of the progressive tax method (IMPTM) and the amount of the progressive tax method (APTM),but neither provides strong support in terms of specific and exact digits and theorles.TO further conform tO the principle of equity and efficiency in LVIT,this research paper aims to discss: (1) the defect in the current system of LVIT. (2) decide upon the appropriate method to be adopted after comparison between the MPTM and the APTM. Chapter 2 consists of statements of LVIT theories and retrospection of related essays.The six sections of this chapter clarify: (1) the theory of LVIT. (2) the definition of tax base and categories of tax rate structure. (3) the principles of equity and efficiency in LVIT. (4) the shifting and incidence in LVIT. (5) a comparison between realization basis and accural basis. (6) the distinction between long-term and short-term land holding;the discrimination between land investment and speculation. Chapter 3 states the historical changes in LVIT and comments thereon.Six tables have been compiled to clarify the six stages of the historical changes since 1954, when the Equalization of Land Rights Act was initiated. The articles discussed include(1)the development of legislation concerning LVIT (2) an analysis of the tax base,tax rate and tax revenues of LVIT (3) a comparison between LVIT and individual income tax (4) a comparison between the MPTM and the APTM. Chapter 4 is an empirical study, of 21,OO0 samples selected from Taipel city within the time span off 1967 to l985.Through computer detecting and hypothesis testing.the date is credible. The analysis shows that the largest taX revenues derived from the first stage (Aug.1954-Feb.1964) and its nationalization of land value increment was the best. If Taipei city is divided into new and old districts,the analysis shows that the average tax rate of the new district is larger than that of the old one under heMPTM,while under the APTM the result is just the opposite.We also verify that the shifting of LVIT actually exists while the simutaneous-equation model of land market is solved.In this chapter,we contribute the major causes for land value changes to rapid growth of economies,public expenditure and population by means Of factor analysis and regression analysis.So,natural increment of land value should un－ oubtedly go to the public in order to conform to the principle of equity and efficiency in taxing. Chapter 5 analyses the long-term changes of LVIT throuhg simulation using DYNAMO. In view of nationalization of land value increment,this chapter verifies that model 4-9-l may correct the defect Of the current MPTM (model 4-9-4),and avoid difficulty in setting a tax grade under the APTM as well. Chapter 6 draws conclusions and Offers suggestions.According to the research results,the current MPTM is better than the APTM which the Sept. 13,1984 con-ference of Executive Yuan decided (model 4-IO-I). But with the rough multiple grade and the harge marginal rate,the current MPTM should be adjusted by reducing the multiple grade by one half and thus the marginal rate becomes 5％.In addition,a 100％ rate of LVIT should not be adopted because it wilI deter the utilization of land.