This study includes the conditions of air carriage according to the Montreal Convention and compares with the previous convention which is the Warsaw Convention. The conditions of air carriage according to the Montreal Convention are divided to two main conditions: the existence of contract to carry people, luggage or goods performed by aircraft for reward, and the international character to contract of air carriage. The Montreal Convention had to avoid criticism which faces the Warsaw Convention in regard to the conditions of air carriage, and had to organize these conditions by harmonious way with international trade requirement, because the Montreal Convention is developer convention to the Warsaw Convention.