A system consisting of an air stripping unit, an inhibitor removal basin, an aerobic basin, and an anoxic basin was investigated for nitrogen removal from coal gasification plant stripped gas liquor containing high-strength organic, nitrogenous compounds. Nitrite oxidation, followed by the reduction of nitrite to nitrogen gas, was adopted for nitrogen removal. The free ammonia concentration in the coal gasification plant stripped gas liquor was obtained by modified empirical method. The optimum reaction temperature, pH, and ammonia.N concentration in the feeding solutions for the ammonia oxidation to nitrite were 30 C, pH 8.0, and less than 200mg/L, respectively. Over 98% of the organic compounds in the wastewater, including phenol, O-cresol, m-cresol, quinoline, and benzene, were removed using the nitrogen removal system by incorporating an inhibitor removal basin. An inhibitor removal basin accelerates ammonia oxidation rate and enhances settleability. This system provides a much faster nitrogen removal rate and less consumption of external carbon sources when compared to conventional nitrogen removal system combined with nitrification and denitrification.