Abstract: The wet flue gas denitrification test was conducted for the exhaust gas from sorbent desulfurization unit using urea/O3 solution in a packed column. The effect of the experimental parameters of flue gas flow, ozone flow and the stages of ozone oxidation were investigated. The laboratory tests show that the optimum process conditions are 8.6 m3/h of flue gas, 1.5 m3/h of O3 and three stage ozone oxidation. At the above conditions, the removal ratio of NOX using urea/O3 solution technology can reached 99.9%, NOX content in wet flue gas is below 100mg/m3. The results compared with that of urea solution/absorption and supergravity technology indicate that the urea/O3 solution denitrification technology exhibits higher removal efficiency towards NOX in flue gas.