As a clean-up method for benz(a)anthracene (BAA)contaminated soils (initial cone.: 500 mgkg(-1)), Fenton oxidation followed microbial treatment was carried out. First, we investigated the effect of the amounts of adedd of ethanol, Fe2+, and H2O2 on BAA removal, the results demonstrating that 0.75 or 1.0 ml of ethanol, 0.2 ml of 0.5 M Fe2+, and 0.25 or 0.3 ml of 30% H2O2 per 1g of Kawazuna or Taisekido were ophnal. Second, under these addition amounts, 51% or 43% of bent (a) anthracene-7,12-dione (BAADI) was generated during oxidation of 97% BAA for Kawazuna or Taisekido, respectively. Third, when the biodegradability of BAA-contaminated Taisekido before and after Fenton oxidation was competed, it was found that 98% of BAADI was degraded after 63 d in comparison with only 12% of BAA over the same period. The results demonstrated that Fenton oxidation enhances the biodegradability of BAA through BAADI.