In this article, the electrochemical behavior of emodin at multi-wall carbon nanotube modified glassy carbon electrodes (MWNTs/GCE) was studied. The result showed that MWNTs/GCE had high electrocatalytic activity for emodin. And the electrocatalytic redox process was a two-charge-two-proton process. Diffusion coefficient (D(R)) of 8.403 x 10(-5) cm(2) s(-1) of emodin was obtained. Further experiments demonstrated that the oxidative peaks increased linearly with emodin concentrations in the range of 1.0 x 10(-6) to 1.0 x 10(-4) M with a limit of detection of 3.0 x 10(-7) M. This electrochemical method was accurate and reliable, therefore, it might provide a novel way for emodin detection.