Solubility enhancements of trichloroethene (TCE), perchloroethene (peE) and their mixture (TCE-PCE) by mixed nonionic and anionic surfactant, Triton X-IOO (TXIOO) and sodium dodecylbenzene sulfonate (SOBS) in ONAPU water systems were presented. Their solubilization extent of TCE by mixed TX I OO-SOBS at the total mass ratios of 3: I, I: I and I: 3 was much larger than by single TX1 00 and even larger than by single SOBS at ratios of 1: I and I: 3. The solubilization extent of PCE by mixed TXIOO-SOBS was between those by single TXIOO and single SOBS. In the mixed TCE-PCE system, the solubilization extent of TCE or PCE by mixed TX I OO-SOBS at the ratios of I: I and I: 3 was larger than by single SOBS while less than by single TXIOO at a greater surfactant concentration. TXIOO partitioning into the organic phase dictated the solubilization extent. SOBS reduced greatly the partition loss of TX I 00 into organic phase. The extent of partition decreased with increasing the amount of SOBS. The mutual affinity of SOBS and TXIOO in the mixed micelle controlled the partitioning ofTXIOO into ONAPL phase.