Abstract: As nations have expressed their concern about the safety of the aircraft and of persons or property therein, and have manifested their desire to curb unruly and disruptive behaviors on board aircraft, through several years of effort, the Montréal Protocol to amend the Tokyo Convention of 1963 (Convention on Offences and Certain Other Acts Committed on Board Aircraft) has been adopted at the International Air Law Conference held under the auspices of ICAO in April 2014. The Montréal Protocol has momentously modified the Tokyo Convention in respect of the application scope of the Convention, the jurisdiction rules regarding to competence of exercising jurisdiction over offences and acts committed on board aircraft, and the rules regarding to the In-flight Security Officers (IFSOs). The effort of making these amendments is valuable, in spite of that, comparative analysis of the provisions of the Montréal Protocol and the Tokyo Convention, and detailed examination of the provisions of the Protocol itself, both indicate that the amendment made by the Protocol is not mature enough and has non-ignorable flaws. The Montréal Protocol of 2014 is a dissatisfactory legal instrument and is hardly to entry into force in the near future.