Abstract: Based on the sensitization effect of hydroquinone on the chemiluminescence (CL) reaction between luminol and potassium periodate in an alkaline medium of 0.10 mol·L-1 KOH,a chemiluminescence method for the determination of hydroquinone was proposed.Linear relationship between the magnitude of CL-intensity and the concentration of hydroguinone was obtained in the range of 1.0×10-8-1.5×10-7mol·L-1,with a detection limit of 8.5×10-9mol·L-1.In its application to the determination of hydroquinone in water,values of recovery found by standard addition method were in the range of 93.4%-104.4%.Mechanism of the sensitization effect on the CL-reaction was also discussed.