In order to explore the removal mechanism of long-chain alkanes in the Fenton system with iron bound to soil organic matter (Fe-SOM), this study carried out 16 groups of experiments to compare the oxidation efficiency of the long-chain alkanes in the Fenton system with Fe-SOM and with typical Fe (Fe unbound to SOM) (total petroleum hydrocarbon (TPH) concentration was 9068 mg/kg). The results showed that the long-chain alkanes removal (C-21-C-30) in the Fenton system with Fe-SOM was up to 361-380 mg/kg (73%-77%), which was 1.6 times higher than that achieved in the Fenton system with typical Fe. The highest removal efficiency of the long-chain alkanes was for C-27, i.e., up to 77%, which indicated that the long-chain alkanes in soil could be removed with a high efficiency in the Fenton system with Fe-SOM. Compared with Fenton system with typical Fe, Fenton system with Fe-SOM can achieve a higher removal efficiency of the long-chain alkanes and a lower residual concentration of long-chain alkanes in aqueous phase. In this system, the H2O2 decomposition is rapid, and the existence of the hydroxyl radicals (center dot OH) is short. The results indicated that the long-chain alkanes oxidation in Fe-SOM system is different from the indirect oxidation in a typical Fe system. This non-indirect oxidation with Fe-SOM was not limited by the short existence of the center dot OH, and these were the reasons for highly efficient oxidation of the sorbed long-chain alkanes in soil.