Abstract: The accelerated environment experiment was performed to simulate natural parking environment, which affected 2A12-T4 aluminium alloy used in aircraft after different calendar years. The detail fatigue rating (σDFR) of specimens were calculated according the data from fatigue test, and the curve of σDFR versus parking time was fitted by the functional equation. The results show that the detail fatigue rating of materials declined linearly with prolonging parking time. The error between calculated value of σDFR by functional equation and actual value by test of specimen from a retired airplane parking for 12 years under natural environment was small.