Established a method for detecting polycyclic aromatic hydrocarbons (PAHs) in petroleum contaminants.The method employed com. available silica and alumina mixed filler solid phase extraction(SPE) cartridge for grouping alkanes and PAHs in the sample group.Exptl. results show that recoveries of alkanes and PAHs rang from 85.6% to 104.9%, the efficiency of grouping is superior that eliminating the interference of alkanes to PAHs' detected method.On the basis of this study, content of PAHs in petroleum samples can be accurately obtained after purified and tested, recoveries of PAHs ranged from 85.3% to 105.9%, the relative standard deviation(RSD, n=5)ranged from 2.2% to 7.3%, reproducibility of this study was excellent.The method was user-friendly, high sensitivity, and accurate for PAHs determination of petroleum samples.