The solubilities of 4-nonylphenol in five kinds of hydroxypropylcyclodextrin (HP-CDs) solutions were investigated in order to evaluate them for soil remediation. The relative aqueous-phase concentration of 4-nonylphenol linearly increased with the increasing HP-CD concentration. The addition of HP-beta -CD (degree of substitution, D,S, = 0.6) produced the largest change because the inner core of HP-beta -CD is the most hydrophobic. The solubility of 4-nonylphenol in the HP-CD solutions depended upon the cavity diameter and the degree of HP-CD substitution. Both ozone and activated carbon treatments have been using for removing organic compounds and foul odor compounds from tap water. As the inclusion complexes moved into the groundwater, the ozone degradation of the inclusion complexes was estimated. The 4-nonylphenol-HP-CD inclusion complexes were easily degraded by ozone. The degree of degradation increased with the increasing ozonization time. Weakly acidic compounds were produced from the 4-nonylphenol-HP-CD inclusion complexes by ozonization, HP-CDs could be used for the removal of 4-nonylphenol from soil,