Abstract: This research aimed to study the solubilization of surfactants to polycyclic aromatic hydrocarbons (PAHs) under the co-existence of a variety of diesel hydrophobic organic contaminants (HOCs).Anionic surfactants LAS and SDS,nonionic surfactants TW 80 and TX 100,and biosurfactants rhamnolipids and alkyl polyglucosides were selected for the assessment of diesel solubilization.LAS,TX 100 and rhamnolipids were further screened out for the solubilization of PAHs in diesel.Results showed that the order of solubilization of diesel was rhamnolipids > TX 100 > alkyl polyglucosides > TW 80 > LAS > SDS.With the co-existence of many diesel constituents,a favorable linear relationship between apparent solubilities of PAHs and surfactant concentrations was observed.The order of solubilization of PAHs in diesel was rhamnolipids > TX 100 > LAS. Rhamnolipids which have lower critical micelle concentrations (CMC) and more complicated molecular structures could form much more and bigger micelles,which was advantageous for the solubilization of diesel and PAHs.