Abstract: Flight delay is becoming a more and more prominent issue in the air carriage contract dispute, and gradually begins to exist as "normal delay". However, current international treaties and domestic legislations share no consistent provision on the definition, nature and responsibility of flight delay. In fact, there is a reasonable delay of flight delays and unreasonable delay in the points. Accordingly, if a carrier is in the event of a reasonable delay, it should not be exempt from the Due Diligence anyway; whereas in the event of an unreasonable delay, the carrier should be liable for losses. The "Service Standards for Abnormal Flight at Chongqing Jiangbei International Airport", as the first standard promised and specified by the carrier, although it clearly defines that economic compensation must be given to flight delays over 4 hours caused by the carrier, compared with countries with mature aviation laws, we still have a gap on the compensation amount and detailed obligations for carriers.