This thesis explores the topic of protection of foreign direct investment in international business law. The literature review covers the definition of FDI, FDI schemes, advantages of FDI, FDI and the protection of national interests, investors, investment, liberalization of foreign direct investment, and controls by the host state. The international laws and regulations section covers FDI in international perspective, TFEU treaty, OECD, USMCA, WTO and GATT, FCN treaties, state responsibility and attribution, and investment insurance. The conclusion summarizes the key points of the thesis