Abstract: The downed Malaysia Airlines Flight MH17 is a human tragedy. The top priority of air transport development is to ensure flight safety and security. There should be unified technical standard for aircraft operation and uniform rules for air traffic which should be subject to uniform air traffic control. Laws and regulations for air navigation safety and security have been established systematically. Still there are many things that need to be done. International society is composed of sovereign states. In the international aviation relations, sovereign states play an important role. The "legalization" of international relations has become a general trend. The international rule of law needs to be strengthened and any state who dares to violate peremptory norm of international law should bear state responsibilities in order to prevent the tragedy from happening again. Thus the safety and security of air navigation can be effectively safeguarded.