Phenol degradation was investigated by electrodeless ultraviolet irradiation.The effect of initial concentration,PH and H2O2 on the degradation of phenol were studied.Results showed there are maximum rate of phenol degradation when the concentration of phenol was 0.02 mg mL-1,PH was 4,and illumination time was 60 min and adding 6% H2O2 4 ml.