Abstract: It was found that in an alkaline medium of 0.05 mol·L-1 NaOH solution,the intensity of chemiluminescence (CL) produced by the reaction between KIO4 and luminol was notably enhanced by the presence of pyrogallol.On the base of this fact,a FI-CL method for determination of pyrogallol in water was proposed.Under optimum condition for the CL reaction,linear relationship was obtained between the magnitude of increase in CL intensity (ΔI) and the concentration of pyrogallol (C in mg·L-1) in the ranges of 1.0-100 μg·L-1 and 0.1-2.0 mg·L-1,with detection limit of 0.78 μg·L-1 (3σ).Precision of the method was tested at the concentration level of 10 μg·L-1 of pyrogallol for 11 determinations,value of RSD obtained was 3.9%.The proposed method was used in the determination of pyrogallol in samples of tap water,river water and industrial waste water,and recovery was tested by standard addition method giving values of recovery in the range from 95.7%-104.1%.