Abstract: The electrochemical behaviors of vitamin B₆(VB₆) were studied by cyclic voltammetry and chronocoulometry in different pH phosphate buffers.The results showed that VB₆ underwent an irreversible electrooxidation with four-electron transfer.VB6 was oxidized to a radicalwhich contained carbonyl structure in basic and neutral medium and was oxidizcd to γ-lactone in acidic medium,The electrooxidative products have electroactivity and a two step quasi-reversible redoxreaction can take place.The chemical detection showed that VB₆ was oxidized to form carbonylcompound in basic and neutral medium,but not in acidic medium. The UV-SEC (spectroelectrochemistry)experiments showed that there were different absorption spectra of VB₆ inbasic-neutral and acidic media with different electrolysis times.On the basis of the above results, the electrochemical reaction path way of VB6 is presented in different pH media.