This lecture aims to serve as an introduction to the legal regulation of international law. We will focus not on the economic aspects but on the legal ones. We will discuss "three levels" of international trade law relationships (i.e. public law, private law and the EU law implications for international law), then we will explain ways, how law regulates commercial law relationships between private individuals (i.e. international businesspeople, merchants etc.), and finally we will focus on one of the most important international conventions in international trade - the UN Convention on Contracts for the International Sale of Goods (a.k.a. the CISG).