Abstract: The pretreated glassy carbon electrode (GCE) was modified by dropping 10 μL of 1.0 g·L-1 suspension of functionized multi-wall carbon nanotube (MWCNT) in N,N′-dimethyl-formamide to the surface of MWCNT,and dried in air.Then the acid chrome blue K (ACBK) was electro-polymerized onto the surface of the MWCNT.In testing for the electrochemical behavior of the modified electrode,PACBK/MWCNT/GCE,excellent electrocatalytic effect and high selectivity toward its reaction with p-benzenediol (p-BZD) were observed.Determination of p-benzenediol was performed satisfactorily in the presence of its isomers.Linear relationship between the anodic peak current and the concentration of p-BZD was obtained in the range of 1×10-6-1×10-4mol·L-1 with a detection limit of 1×10-7mol·L-1.In its application to the analysis of water samples,results obtained were in consistency with the results obtained by spectrometry.