Source of international economic law is a standard for demarcating border of legal science and other social sciences. The object of regulation by international economic law is a relation of international economic administration and supervision, not of international business transaction. So the only sources of international economic law are international treaty(ies), international custom(s) and general principle(s) regulating relation(s) of international economic administration and supervision, and are the domestic economic law(s) and rule(s) governed by international law, for international economic law do not regulate relation of domestic economic administration and supervision.