國際投資法為國際經濟法下之分支，是規範國際私人投資關係與保護外 國投資的法律制度，包括各國簽訂的投資協議及各國國內對外國投資人之獎 勵與限制法規、保護措施及爭端解決制度等17，所涉及的主體為資本輸出國
、外國投資人、地主國及被投資方所形成的六面關係，因此國際投資法之法 源可分為二個法律層次---國際法法源及國內法法源。
一、國際法法源
（一）條約
國際投資法的國際法法源絕大多數是來自於雙邊投資條約，但是部分的 條約是由全球性或區域性的多邊條約而來。
1. 全球性多邊條約
多邊條約可說是簽約國家接受國際法原則的證據18，目前最重要的多邊 條約有二：分別是世界貿易組織（The World Trade Organization，簡稱 WTO
17 參考周顯志主編，國際投資法教程，中國財政經濟出版社，1998 年，頁 8。
18 參考 Sornarajah, M., The International Law on Foreign Investment, p. 87.
） 及 多 邊 投 資 擔 保 機 構 公 約 （ Convention Establishing The Multilateral Investment Guarantee Agency，簡稱 MIGA）。
（1） 世界貿易組織
依 據 1994 年 的 「 馬 爾 喀 什 設 立 世 界 貿 易 組 織 協 定 」 （ Marrakesh Agreement Establishing The World Trade Organization），WTO 於 1995 年 1 月 1 日正式成立。WTO 原本處理的議題是關於各國的商品貿易事務，然隨 著國際貿易的發展，與貿易相關的領域也紛紛成為 WTO 會員國所關心、欲 做整合規範的議題，烏拉圭回合多邊貿易談判制定了「與貿易有關的投資措 施協定」（Agreement on Trade-Related Investment Measure，簡稱 TRIMs）19， TRIMs 所規範的是各國對貨物貿易有關的投資措施20，但是非適用於所有投
19 參考 Mavroidis, P. C., The General Agreement on Tariffs and Trade, Oxford University Press, 2005, pp.
1-9; Cass, D.Z., The Constutionalization of The World Trade Organization, Oxford University Press, 2005, pp. 5-15; Brewer, T.L., Young, S., The Multilateral Investment System and Multinational Enterprises, pp. 121-123; 黃立、李貴英、林彩瑜合著，WTO 國際貿易法論，元照出版，3 版，
2002 年，頁 9~27；Stoll, P.T., Schorkopf, F.，南京大學中德法學研究所譯，世界貿易制度與世界 貿易法，法律出版社，2004 年，頁 17~19；曹建明、賀小勇，世界貿易組織，法律出版社，2 版，2004 年，頁 7~26。
20 Art. 1 of TRIMs: “This Agreement applies to investment measures related to trade in goods only (referred to in this Agreement as "TRIMs").”
參照 WTO 網站：http://www.wto.org/english/docs_e/legal_e/legal_e.htm。最後瀏覽日：2008/2/2。
參考 The Legal Texts---The Results of the Uruguay Round of Multilateral Trade Negotiations, Cambridge University Press, 1994, pp. 143-146; Kennedy, K., A WTO Agreement on Investment: A Solution in Search of a Problem?, 24 U. Pa. J. Int'l Econ. L. 77, 2003; Brewer, T.L., Young, S., The Multilateral Investment System and Multinational Enterprises, pp. 124-125.
21 Art. 2 of TRIMs “1.Without prejudice to other rights and obligations under GATT 1994, no Member shall apply any TRIM that is inconsistent with the provisions of Article III or Article XI of GATT 1994.
2. An illustrative list of TRIMs that are inconsistent with the obligation of national treatment provided for in paragraph 4 of Article III of GATT 1994 and the obligation of general elimination of quantitative restrictions provided for in paragraph 1 of Article XI of GATT 1994 is contained in the Annex to this Agreement.”
參照 WTO 網站：http://www.wto.org/english/docs_e/legal_e/legal_e.htm。最後瀏覽日：2008/2/2。
22 Art. 4 of TRIMs: “A developing country Member shall be free to deviate temporarily from the provisions of Article 2 to the extent and in such a manner as Article XVIII of GATT 1994, the Understanding on the Balance-of-Payments Provisions of GATT 1994, and the Declaration on Trade
合該義務。
服務貿易總協定（General Agreement on Trade in Services,簡稱 GATS）
亦是烏拉圭回合談判中的三大議題之一。GATS 共列舉了四種服務貿易的形 式，分別為跨境服務（crossborder supply）、境外消費（consumption abroad
）、商業呈現（commercial presence）與自然人呈現(（presence of natural persons
）23。商業呈現即是指透過外國投資設立、收購或參與經營各種商業機構，
Measures Taken for Balance-of-Payments Purposes adopted on 28 November 1979 (BISD 26S/205-209) permit the Member to deviate from the provisions of Articles III and XI of GATT 1994.”
參照 WTO 網站：http://www.wto.org/english/docs_e/legal_e/legal_e.htm。最後瀏覽日：2008/2/2。
23 Art. 1(2) of GATS: “For the purposes of this Agreement, trade in services is defined as the supply of a service:(a) from the territory of one Member into the territory of any other Member; (b) in the territory of one Member to the service consumer of any other Member; (c) by a service supplier of one Member, through commercial presence in the territory of any other Member; (d) by a service supplier of one Member, through presence of natural persons of a Member in the territory of any other Member.”
參照 WTO 網站：http://www.wto.org/english/docs_e/legal_e/legal_e.htm。最後瀏覽日：2008/2/2。
參考 Brewer, T.L.,Young, S., The Multilateral Investment System and Multinational Enterprises, pp.
126.
24 Art. 16 of GATS: “(1) With respect to market access through the modes of supply identified in Article I, each Member shall accord services and service suppliers of any other Member treatment no less favourable than that provided for under the terms, limitations and conditions agreed and specified in its Schedule.
(2) In sectors where market-access commitments are undertaken, the measures which a Member shall not maintain or adopt either on the basis of a regional subdivision or on the basis of its entire territory, unless otherwise specified in its Schedule, are defined as (a) limitations on the number of service suppliers whether in the form of numerical quotas, monopolies, exclusive service suppliers or the requirements of an economic needs test; (b) limitations on the total value of service transactions or assets in the form of numerical quotas or the requirement of an economic needs test; (c) limitations on the total number of service operations or on the total quantity of service output expressed in terms of designated numerical units in the form of quotas or the requirement of an economic needs test; (d) limitations on the total number of natural persons that may be employed in a particular service sector or that a service supplier may employ and who are necessary for, and directly related to, the supply of a specific service in the form of numerical quotas or the requirement of an economic needs test; (e) measures which restrict or require specific types of legal entity or joint venture through which a service supplier may supply a service; and (f) limitations on the participation of foreign capital in terms of maximum percentage limit on foreign shareholding or the total value of individual or aggregate foreign investment.”
參照 WTO 網站：http://www.wto.org/english/docs_e/legal_e/legal_e.htm。最後瀏覽日：2008/2/2。
之要求等形式，藉指定之數量單位，限制服務營運之總數或服務之總生產數 量；D.以配額數量或要求經濟需求檢測，限制特定服務行業得僱用自然人之 總數，或限制某一服務提供者得僱用與特定服務之供給直接有關且必要之自 然人總數；E.限制或要求服務提供者，以特定之法人型態或合資方式始得提 供服務；及 F.以設定外國人持股比例或個人總額或全體外資總額等上限方式
，限制外資之參與。
而在國民待遇原則下，除了對外國投資人之待遇不得低於本國國民外，
GATS 第 17 條第 2、3 款另規定為符合國民待遇的要求，會員可以對所有其 他會員之服務及服務提供者偍供與其給予自己服務及服務提供者，或者形式 上相同待遇，或者形式上有差別待遇之方式，但是若修訂的競爭條件該待遇 改變競爭條件，使會員自己之服務或服務提供者較其他會員之服務或服務提 供者有利，則該項形式上相同或形式上有所不同之待遇都應被視為不利之待 遇，違反了國民待遇原則25。
（2） 多邊投資擔保機構
世界銀行於 1985 年 10 月在漢城召開年會通過多邊投資擔保機構公約，
建立了多邊投資擔保機構，是世界銀行底下的第三個機構，目前共有 171 個 會員國26。MIGA 的成立目標是鼓勵會員國間的生產性投資的流動，特別是 對發展中國家，以補充國際復興開發銀行、國際金融公司與其他國際開發金 融機構的活動。為了達成此目標，MIGA 的任務有三：
A.對會員國內來自其他會員國投資所生的非商業風險提供擔保，包括共 同保險及分別保險。MIGA 所指的非商業風險包括貨幣匯兌風險、徵收或類 似徵收之風險、戰爭風險與內亂風險，另外特別包含了違約風險27；
25 Art. 17 of GATS: “(1) In the sectors inscribed in its Schedule, and subject to any conditions and qualifications set out therein, each Member shall accord to services and service suppliers of any other Member, in respect of all measures affecting the supply of services, treatment no less favourable than that it accords to its own like services and service suppliers.
(2) A Member may meet the requirement of paragraph 1 by according to services and service suppliers of any other Member, either formally identical treatment or formally different treatment to that it accords to its own like services and service suppliers.
(3) Formally identical or formally different treatment shall be considered to be less favourable if it modifies the conditions of competition in favour of services or service suppliers of the Member compared to like services or service suppliers of any other Member.”;
參照 WTO 網站：http://www.wto.org/english/docs_e/legal_e/legal_e.htm。最後瀏覽日：2008/2/2。
參考 Brewer, T.L., The Multilateral Investment System and Multinational Enterprises, pp. 126,127.
26 參照 MIGA 網站：http://www.miga.org/quickref/index_sv.cfm?stid=1577。最後瀏覽日：2007/11/22。
27 Art. 11 of Convention Establishing The Multilateral Investment Guarantee Agency: “(a)Subjectto the provisions of Sections (b) and (c) below, the Agency may guarantee eligible investments against a loss
B.提供輔助以促進發展中之會員國的投資流動；
C.必要時，執行其他為達設立宗旨的附隨權力。28
MIGA 定有爭端解決規定，如有爭端，應循談判、調解或仲裁程序解決
。且在利用調解或仲裁程序前，MIGA 公約規定應先行談判程序29，若是利 用調解或仲裁程序，會員國可利用 ICSID 機構進行之。
2. 區域性多邊條約
區域性多邊條約通常與區域經濟整合相關連，目前各洲都成立了該區域 之經濟組織。歐洲有歐洲經濟共同體（European Economic Community）；美 洲有北美自由貿易協定、中美洲共同市場、南美洲共同市場（安地斯共同市 場、加勒比海共同體）；亞洲有東南亞國協（Association of Southeast Asian Nations，簡稱為東協 ASEAN）；而非洲亦有各分區的區域的共同體，如非 南共同體、西非國家經濟共同體、非洲聯盟等30。本論文就歐洲、美洲、亞 洲三地具代表性之區域經濟組織分析之。
（1） 歐洲經濟共同體
在 歐 洲 ， 投 資 保 護 一 直 是 歐 洲 經 濟 共 同 體 （ European Economic Community）與歐洲自由貿易區（European Free Trade Area，簡稱 EFTA）所 關注的法律議題。EFTA 建立於 1960 年的斯德哥爾摩條約（Stockholm
resulting from one or more of the following types of risk: (i) Currency Transfer…(ii) Expropriation and SimilarMeasures…(iii) Breach ofContract…(iv) Warand CivilDisturbance…”
參照 MIGA 網站：http://www.miga.org/quickref/index_sv.cfm?stid=1583。最後瀏覽日：2008/2/2。
28 Art. 2 of Convention Establishing The Multilateral Investment Guarantee Agency: “Theobjectiveof the Agency shall be to encourage the flow of investments for productive purposes among member countries, and in particular to develop member countries, thus supplementing the activities of the International Bank for Reconstruction and Development (hereinafter referred to as the Bank), the International Finance Corporation and other international development finance institutions.
To serve its objective, the Agency shall: (a) issue guarantees, including coinsurance and reinsurance, against non-commercial risks in respect of investments in a member country which flow from other member countries; (b) carry out appropriate complementary activities to promote the flow of investments to and among developing member countries; and (c) exercise such other incidental powers as shall be necessary or desirable in the furtherance of its objective.
TheAgency shallbeguided in allitsdecisionsby theprovisionsofthisArticle.”
參照 MIGA 網站：http://www.miga.org/quickref/index_sv.cfm?stid=1583。最後瀏覽日：2008/2/2。
29 Art. 2 of Annex II of Convention Establishing the Multilateral Investment Guarantee Agency: “The parties to a dispute within the scope of this Annex shall attempt to settle such dispute by negotiation before seeking conciliation or arbitration. …”
參照 MIGA 網站：http://www.miga.org/quickref/index_sv.cfm?stid=1583。最後瀏覽日：2008/2/2。
30 參考 Philippe Sands, Pierre Klein, Bowett’s Law of International Institutions, 5thedition, Sweet &
Maxwell, 2001, pp. 215-217, 221, 243-255.
Convention Establishing Free Trade Association），該條約內容在規範各會員 國間關於貿易合作及自由流通等事項，EFTA 在 2001 年瓦都茲條約（Vaduz Convention）增修斯德哥爾摩條約時，特別增補了第 9 章的投資章，內容規 範了投資的範圍及原則、國民待遇原則、金融市場規範、相互承認、資金流 通與例外規定31。
歐洲經濟共同體為歐洲共同體（European Community）的前身。法國、
德國、義大利、荷蘭、比利時和盧森堡在巴黎簽訂了「建立歐洲煤鋼共同體 條約」，又稱「巴黎條約」（Treaty of Paris），歐洲煤鋼共同體(European Coal and Steel Community)於 1952 年 7 月 25 日正式成立。1957 年 3 月 25 日，這 六個國家在羅馬簽訂了「建立歐洲經濟共同體條約和歐洲原子能共同體條約
」，通稱「羅馬條約」（Treaty of Rome），1958 年 1 月 1 日，歐洲經濟共 同體和歐洲原子能共同體（European Atomic Energy Community）正式組建
。1992 年馬斯垂克條約第 1 條將歐洲經濟共同體更名為歐洲共同體。歐洲
。1992 年馬斯垂克條約第 1 條將歐洲經濟共同體更名為歐洲共同體。歐洲