Abstract: No clear definition and detailed rules have been provided for the issue of delay in civil aviation so far. Such indeterminacy has further confused or delayed th e proper resolution in practice. The issue of delay in international air transpo rtation is itself a serious problem requiring international co-ordinance. Warsa w Convention took the first step to put the burden on the carrier and regulate i ts liability. When approaching the new century, increasing occurrence of interna tional aviation brings forward the demand on more detailed rules on delay, which to a certain extent contribute to the new Montreal Convention. The Warsaw Conve ntion shall remain as the basic document for the present discussion and the pape r concludes by offering suggestions for further improvement in resolving dispute s over liability resulting from delay in civil aviation.