Because　of　the　chemical　reaction　between　Cr(VI)　ions　and　glutathione,　the　peak　reduction　current　of　Cr(VI)　ions　decreases　while　adding　glutathione　(GSH)　into　a　K2Cr2O7/H2SO4　solution.　Thus　the　concentration　of　GSH　can　be　detected　indirectly　by　differential　pulse　voltammetry　(DPV)　analysis.　This　electrochemical　indirect　method　was　used　to　study　the　adsorption　of　GSH　on　multi-walled　carbon　nanotubes　(MWCNTs)　and　activated　carbon　(AC),　and　can　be　used　to　determine　the　equilibrium　relationship　between　GSH　adsorption　and　its　concentration.　Unlike　the　result　obtained　from　the　active　carbon,　GSH　adsorption　on　MWCNTs　agrees　better　with　that　predicted　by　the　Freundlich　equation　compared　to　that　predicted　by　the　Langmuir　equation.　The　morphologies　of　MWCNTs　and　activated　carbon　were　observed　with　scanning　electron　microscopy　(SEM)　and　transmission　electron　microscopy　(TEM).　The　abundance　of　aggregated　pores　in　MWCNTs　is　beneficial　for　the　diffusion　and　adsorption　of　small　GSH　molecules,　suggesting　that　MWCNTs　could　be　developed　as　an　adsorbent　for　small　molecular　substances.