1965 年「解決國家與他國國民間投資爭端公約」創設國際投資爭端解決中心，建立以仲裁程序為主的投資人對地主國爭端解決機制，投資人無須仰賴母國行使外交保護權，得遂行投資人對地主國仲裁以落實國際投資條約之實體保障。惟對跨國投資之中小企業而言，鉅額仲裁費用形成仲裁利用途徑之障礙，不但妨礙中小企業投資保障實體權益之落實，更可能衝擊國際投資爭端解決機制去政治化之發展。國際投資仲裁程序費用，如仲裁機構規費，仲裁庭費用與法律服務費用，動輒達百萬美元以上。中小企業可能無力承擔而放棄仲裁。本文提出減輕仲裁費用負擔之建議方案，包括：仲裁機構規費採差別費率，對中小企業降低收費；涉及中小企業之仲裁案件，當事人選任單一仲裁人以減少仲裁庭費用；仿效世界貿易組織法律顧問中心、設置國際投資法律扶助機構，對中小企業提供免費法律意見諮詢與爭端程序代理；尋求第三方資助仲裁費用等。本文主張，選任單一仲裁人與建立國際投資法律扶助機構最能減輕仲裁費用負擔。建議政府於後續國際投資條約談判過程引入此等措施，以保障中小企業對投資仲裁利用途徑，確保其等實體投資權益之落實。 The 1965 Convention on the Settlement of Investment Disputes between States and Nationals of Other States (ICSID Convention) established the International Centre for Settlement of Investment Disputes (ICSID) and affirmed the use of international arbitration as primary means for resolving disputes between foreign investors and host states. An aggrieved foreign investor no longer needs to rely upon its home state to invoke diplomatic protection once local remedies are exhausted in the host state, but could proceed with investor-state arbitration to seek implementation of substantive protection under a specific international investment treaty. However, for small and medium-sized enterprises (SMEs) involved in international investment, a huge amount of arbitration costs creates a practical barrier to their access to arbitration. Such impediment might not only frustrate the protection of investor’s substantive interests, but also endanger the depoliticization of investment dispute resolution. Costs generated in investorstate arbitration, such as administrative fees, tribunal’s fees and expenses, and lawyer’s fees, could easily exceed millions of US dollars. SMEs are likely to forego arbitration due to lack of funding. This article proposes solutions reducing arbitration costs, including lowering administrative charge rate for SMEs, appointing sole arbitrator, establishing pro bono legal assistant institution in the field of international investment law and dispute settlement procedures, and securing third party funding. Among them, the appointment of a single arbitrator and the creation of a legal clinic for international investment law seem to be the most effective answer. This article recommends that our government consider incorporating such measures into future negotiation of international investment treaties, in order to protect SMEs’ access to investor-state arbitration and ensure the fulfillment of their substantive interests.