Photocatalytic degradation of pyrene on soil surfaces was investigated in the presence of nanometer anatase TiO2 under a variety of conditions. After being spiked with pyrene, soil samples loaded with different amounts of TiO2 (0%, 1%, 2%. 3%, and 4%, w/w) were exposed to UV irradiation for 25 h. The results indicated that the photocatalytic degradation of pyrene followed pseudo-first-order kinetics. TiO2 accelerated the degradation of pyrene generally as indicated by the half-life reduction from 45.90 to 31.36 h, corresponding to the TiO2 amounts from 0% to 4%, respectively. The effects of H2O2, light intensity and humic acids on the degradation of pyrene were also investigated. The degradation of pyrene increased along with increasing the concentration of H2O2, light intensity and the concentration of humic acids. All results indicated that the photocatalytic method in the presence of nanometer anatase TiO2 was an advisable choice for the treatments of PAHs polluted soil in the future. (C) 2009 Elsevier B.V. All rights reserved.