[Objective] The aim of this study was to find a better method to exactly quantify the residual polycyclic aromatic hydrocarbons（PAHs）in the long-term contaminated soil in the field so as to provide basis for the remediation for PAHs contaminated soil.[Method]The comparisons of soxhlet extraction,ultrasonic extraction and shaking extraction were studied in the agricultural soil irrigated with oil sewage over a long period of time.[Result]The total PAHs extracted by soxhlet extraction were the highest（6 873.7 μg/kg）,followed by shaking extraction（6 698.8 μg/kg）and ultrasonic extraction（5 737.6 μg/kg）.Among these methods,the highest extracted 4 and 6 rings PAHs were in the soxhlet extraction,the highest extracted 2 and 5 rings PAHs were in the shaking extraction,and the highest extracted 3 rings PAHs were in the ultrasonic extraction.[Conclusion]This study had provided basis for the selection of the assessment method of residual PAHs in the field soil.
