Abstract: The photooxidative degradation of the landfill leach under solar irradiation by H₂O₂/ferric oxalate complexes was studied. The result indicates that under the initial condition of pH=3.0, ρ（H₂O₂）=460 mg/L and ρ(Fe³⁺+)=20 mg/L, the removal percentage of COD_Cr can reach over 80% in 60 minutes. It is found that the initial pH, ρ（H₂O₂） and ρ(Fe³⁺+) of the solution have significant effects in this photooxidative process. The removal percentage of COD_Cr is higher under solar irradiation than under UV irradiation. Under the selected conditions, using solar/H₂O₂/ferric oxalate complexes to treat the landfill leach has good efficiency.