隨著科技進步，時代潮流之演進，以及一九三○年代多國性企業之興起，國際投資行為已成為推動世界經濟發展之主流。然而有關國際投資行為因涉及二個或二個以上政治、文化、經濟、社會背景不盡相同之國家，無論各國政府各項新制度之建立或投資者本身投資決策之擬定，皆需綜合各項複雜因素加以考慮。尤其國際投資所得課稅問題，牽涉投資者國內國外投資相對租稅負担差異，直接影響投資淨報酬率多寡。近年來，更伴隨公司與股東所得稅合併制度之採行，而成為各國政府探討國際租稅政策或國際投資者選擇投資地區之重要焦點。

大凡國際投資所得之課稅，包括(一)本國人之國外直接投資（成立子公司或分公司）。(二)本國法人或個人之國外證券投資。 (三)外國人之直接投資。(四)外國法人或個人之證券投資所得課稅。由於此等所得之課稅權，涵蓋所得來源國與居住國等不同國家，在各國所得稅不同課稅權原則(屬人主義，屬地主義或折衷主義），以及公司與股東所得稅合併程度（全部合併、部份合併或獨立課稅）與方式（股東階段之股利設算抵繳或公司階段之股利減除優惠）互異之情況下，遂發生不同課稅權國家，同時對同一國際投資所得重複課稅現象。

國際投資所得重複課稅現象，影響國際資本流動甚鉅，各國難透過雙邊租稅協定，多邊租稅協定或單邊租稅減免措施，採取國外所得免稅法，國外稅額減除法，國外稅額扣抵法或其他方法加以防免，然而所採方式有別，其免除重複課稅效果不一而足。基於此，本文除介紹所得稅獨立課征、雙軌稅制、股利減除制、股利部份設算抵繳制或兩稅完全合併制度下，公司與股東國際投資所得課稅規定外，復由國際觀點、國家觀點及投資者觀點，評估不同所得稅制度，為配合世界效率、國冢效率、國際間稅收分配公平、國際間租稅負担公平、國際收支平衡、經濟成長等原則，所應採取防免公司與股東所得稅國際重複課征之方法。

其次，我國當前財經政策，亦在獎勵國際投資以促進經濟發展，惟對國際投資所得之課稅規定不夠詳盡，本文為使「他山之石，足以攻錯」，乃詳述各國對國際投資所得之課稅實務規定。其中包括採行股利部份設算抵繳制度之英國、法國、西德、加拿大，完全合併制度之新加坡，兼採雙軌稅制與股利扣抵制度之日本，以及獨立課稅制度之美國等有關規定之內容，藉以提供我國目前採獨立課稅制或未來採兩稅合併制度之國際投資所得課稅規定參考。

本文得以完成，承蒙恩師陳教授文龍、徐所長偉初、陳教授建昭以及林教授柏生等，提供寶貴意見，此外非常感激好友李美伶、王玲麗、黃慧珍、薛玉枝、許美麗、曾光文及吳永森等鼎力相助。

中文部份：
1.王建煊著，租稅法（臺北：文笙書局，民國七十年五版）。
2.________ ,所得稅問題研究（所得稅制度及實務），財稅訓練教材之二(2)，財政部財稅人員訓練所編印，民國六十二年一月。
3.王建煊、金唯信合著，改進我國營利事業所得稅制之研究，行政院賦稅改革委員會報告書，第三部研究彙編(一)，民國五十九年六月。
4.李榮昇著，關係企業課稅問題之研究，國立政治大學財政研究所碩士論文，民國六十四年六月。
5.林誠二著，「國際租稅問題的探討」，財稅研究，七卷三期，民國六十四年五月。
6.林崑誠著，「多國性公司的課稅問題(下)」，財稅研究，八卷二期，民國六十五年五月。
7.邱康夫著，多國籍企業之經營，編者自印，民國六十三年十二月。
8.陳合良譯：「日本租稅條約概況」，財稅研究，三卷四期，民國六十五年七月。
9.許永邦著，所得稅協定之研究，中國租稅研究會，民國六十六年元月。
10.郭偉烈著，「國際稅法上營利事業所得課稅問題」，財稅研究，十卷五期，民國六十七年九月。
11.游啟璋著，「論課稅管轄權」，財稅研究，九卷二期，民國六十六年三月。
12.趙揚清撰，我國實行公司所得稅制之擬議（臺北：政大財政研究所，民國六十四年七月）。
13.蔡再本著，「多國公司之研究」，財稅研究，六卷六期，民國六十三年六月。
14.劉厚醇著，多國性企業通論，聯經出版事業公司，民國六十六年四月。
15.樊仁裕著，國際租稅之研究，編者自印，民國六十四年八月。
16.戴欽泉著，「綜合所得稅以稅額扣抵法代替所得扣抵法之研究」，財稅研究，七卷三期，民國六十四年五月。
17.蘇琪譯：「日本締結之租稅條約」，財稅研究、四卷一期，民國六十六年一月。
二、英文部份：
1. Bergsten, C.F., Horst, T.& Moran. T. H., American Mul-tinationals and American Interests ( The Brookings Institution, Washington D.C., 1978)
2. Bird, R.M., "International Aspects of Integration " National Tax Journal Vol. 18(3), (September 1975 ) :302-14
3. Breaks ,G.F., "Integration of the Corporate and Personal Income Tax, " National Tax Journal Vol. 22(1) ( March 1969 ) : 39-50
4. Break, G. F. and Pechman, J. A., " Relationship Between the Corporation and Individual Income Taxes National Tax Journal Vol 18(3) ( September 1975 )
5. Chown, J., " The Harmonisation of Corporation Tax in the EEC ", British Tax Review No.1 ( 1976 ) : 39-48
6.________, New International Tax Rules in the United Kingdom, Canadiam Tax Journal Vol. 13, No. 1(1977):69-73
7. Cohen, E.S., "Possible Solutions to Practical Problems in Integration of the Corporate and Shareholder Income Tax ", National Tax Journal Vol. 18(3) ( September 1975 ) : 359-67)
8. Corrigan, E.F., " Interstate Corporate Income Taxation-Recent Revolutions and a Modern Response ", Vanderbilt Law Review Vol. 29 ( 1976) : 423 -42
9. Dexter, W.D., " Taxation of Income From Intangibles of Multistate-Multinational Corporations ", Vanderbilt Law Review Vol. 29(1976):401-21
10. Easm, R. T., "International and Comparative Aspects of Corporate/Shareholder Integration：A view from the United Kingdom " , Bulletin for International Fiscal Documentation , Vol.33(7) (July 1979): 312-16
11. Fiorino, J. and Galvin, A. J., " Corporate Taxation Around the World ", Canadian Tax Journal Vol. 27(2) (March-April 1981): 199-210
12. Frommel, S.N., Taxation of Branches and Subsidiaries in Western Europe, Canada and the USA, (Fred B. Rotbman Inc., 1975)
13. Gibson, R. C., " Imputation Tax Systems in France. Italy, West Germany and the United Kingdom: Wave of the Future? "Canadian Tax Journal Vol. 27(3)(May 1979):347-49
14. Griff , J., "The Effect of U.S. Foreign Direct Investment of the Integration of the Corporate and Personal Income Taxes " , U.S. Treasury Dept. office of Tax Analysis : Paper 22 (1974)
15. Hammer, R. M., " The Taxation of Income From Corporate Shareholders：Review of Present Systems in Canada, France, Germany. Japan and the United Kingdom, " National Tax Journal Vol. 18(3) ( September, 1975) : 315- 34
16. Haney, J. R., " Integration of the Corporate and Individual Income Taxes", National Tax Journal Vol. 30(3) (September 1977): 345-58
17. Harvard Law School, International Program in Taxation：Taxation in the United States (Commerce Clearing House, Chicago, 1963)
18. Holland., D.M. "Some Observations on Full Integration ", National Tax Journal Vol. 18 ( 3 ) (September 1975 ): 353-57
19. Hugh, A. Jr., " International Issues in Corporate Tax Integration ", Law and Policy in International Business, Vol. 10(2)(1978): 461-94
20. Jones, D. P., "Corporations, Double Taxation and the theory of Integration ", Canadian Tax Journal Vol. 27 ( 4) ( July-Aug. 1979): 405-27
21. Mclure , C. Jr., Must Corporate Income Be Taxed Twice ? ( The Brookings Institution, Washington D.C., 1979 )
22.________, " International Aspects of Dividend Relief ", Journal of Corporate Taxation. Vol. 7 (2) (Summer 1980): 137-62
23.________, " Integration of the State Income Taxes : Economics and Administration Factors ", National Tax Journal Vol. 36(1) (March 1981) : 75-87
24.________, A States Report on Tax Integration in the United States " , National Tax Journal Vol. 31 (4) (December 1978 ) : 313-28
25.________, " Integration of the Personal and Corporate Income Taxes : the Missing Element in Recent Tax Reform Proposal, " Harvard Law Review No.88 (January 1975 ) : 532-82
26.________, " Integration of Income Taxes : Why and How " , Journal of Corporate Taxation Vol.2 (Winter 1976 ) : 429-64
27. Mclure, C. Jr. and Stanley S. Survey, " Integration of Income Taxes : Issues for Debute", Harvard Business Review Vol. 55(5)(September-October 1977 ) : 169-81
28.Musgrave, P.B., " International Tax Differentials For Multinational Corporations : Equity A Efficiency Considerations, " Public Finance (1972) : 394-413
29.________, "United States Taxation of Foreign Investment Income : Issues and Arguments ", Combridge Mass Harvard Law School International Tax Program ( 1969)
30. Muten, L., " International Tax Relations", Finance and Development No.2 (June 1971 )：38-60
31. OECD, Fiscal Committee, Draft Double Taxation Convention on Income and Capital ( Paris, 1964 )
32. Plasschaert, S. R. F., " The Treatment of Enterprise Profits in Schedulay And Global Frameworks of Income Taxation" , Bulletin For International Fiscal Documentation Vol.10 (1981): 261-70
33. Price Waterhouse, Doing Business in Canada ( Price Waterhouse Inc., New York, 1979 )
34. ________, Doing Business in France (Price Waterhouse Inc., New York, 1980 )
35, ________, Doing Business in the Germany ( Price Waterhouse Inc., New York, 1980)
36. ________, Doing Business in the United Kingdom ( Price Waterhouse Inc., New York, 1980 )
37. ________, Doing Business in the Singapore (Price Water-house Inc., New York, 1980 )
38. Rotterdam Institute for Fiscal Studies, International Tax Avoidance：General and Conceptual Waterial, Vol. A, (Kluwer Deventer, the Netberlands, 1979 )
39. Sato, M. and Bird, R.M., International Aspects of the Taxation of Corporations and Shareholders, IMF Staff Pappers, Vol. 12 ( 2) (July 1975 ) : 384-455
40. Severiens, J.T., " The Inputation Tax System Reappraisal, Bulletin for International Fiscal Documentation vol.15(4)(1976) : 143-49
41. Survey, S. S., " The Reflection of Integration of Corporation and Individual Income Taxes", National Tax Journal, Vol. 18 (3)
42. U.S. Master Tax Guide 1982 Guide, 65th ed. ( Commerce Clearing House, Chicago, 1981 )
43. Van Den Tempel, A. J., Corporation Tax and Individual Income Tax in the European Communities ( Comission of the European Communities, Brusseles, 1970 )
44.Van Rooijen, M. J., " Interrelationship of Corporation Tax and Income Tax of Schareholders, Bulletin for International Fiscal Documentation, Vol. 33 ( 7 ) ( July 1977 ) : 64-8
45. Van Warderburg , D.A., "France：A Survey of its tax system" , Bulletin for International Fiscal Documentation, Vol. 8-9 (August-September 1980 ) : 345-47
46. Warren, A., " The Relation and Integration of Individual and Corporate Income Tax", Harvard Law Review Vol. 94(4) (February 1981) :721-98
47. Williams, R.G., Comprehensive Aspects of Taxation, revised by A.D.W. Bertram and S. G. Edwards (A Cassell Professional Handbook, London, 1980-81 )
48. Yuji Gomi, Guide to Japanese Taxes 1980- 81(東京財經詳報社發行，1980)