The Warsaw Convention of 1929 for the unification of certain rules of international air transport is the basis of the legal regulation of international air transport. Agreements supplementing the Warsaw Convention: Hague Protocol of 1955, Guatemala Protocol of 1971 amending the Warsaw Convention, Guadalajara Convention of 1961, Montreal Protocol for the Unification of Certain Rules Relating to International Carriage by Air (1975). The Montreal Interim Airline Agreement of 1966, the Montreal Agreement of 1999. The set of norms of these agreements as a whole constitutes the Warsaw System of Regulation of International Air Transport. IATA – a special non-governmental organization, an association of airlines of ICAO member states – is responsible for determining the specific conditions of international air transportation. On May 28, 1999, a significant event took place in the field of international private air law: as a result of the three-week work of the Diplomatic Conference on Air Law held at the ICAO headquarters with the participation of representatives of 121 states and 11 international aviation organizations, the Convention for the Unification of Certain Rules of International Aviation Law was adopted of air transportation (Montreal Convention of 1999), which defines the basic legal conditions of international air transportation in the 21st century. Scientific and technical progress, the rapid development of international air transport, the increase in the safety of its operation made it necessary to expand the scope and more clearly regulate the responsibility of the carrier. This international Convention is designed to provide firm legal guarantees and an adequate level of compensation to persons injured as a result of aviation events, to create a uniform and clear legal regime of responsibility of air carriers for failure to preserve cargo, baggage and delay during their transportation on international lines. On November 4, 2003, the Montreal Convention entered into force. Among the participants of the Convention are such countries as the USA, Japan, Canada, China, the countries of the European Union, including Ukraine. The article examines the early development of the aviation industry and the role of the Warsaw Convention in the construction of rules and mechanisms aimed at protecting the interests of both the carrier and the passenger or cargo owner. The development of the norms of the Warsaw Convention in various protocols is revealed. Such as the Hague Protocol (1955), the Guadalajara Convention (1961), the Guatemala City Protocol (1971) and the Montreal Four Protocols (1975), which significantly modernized the provisions on air transport regulations, as seen in the Montreal Convention (1999).