Ionic liquid-reduced-graphene oxide modified electrode (IL-rGO/GCE) was fabricated using a simple and green method, and it exhibited good electrochemical response on Sudan I. The electrochemical behavior of Sudan I was studied sufficiently, and two electrons and two protons are involved in the electrochemical process of Sudan I at IL-rGO/GCE. Some dynamic parameters such as the diffusion coefficient (D) and adsorption capacity (Gamma*) were calculated as D = 1.43 x 10(-6) cm(2)/s, Gamma* = 1.97 x 10(-10) mol/cm(2) by chronocoulometries. Meanwhile, supported by cyclic voltammetry experiments, the possible electrochemical reaction mechanism of Sudan I was proposed, which is E1CE2 process. Finally, the effect of initial potential and the scanning direction on the electrochemical reaction of Sudan I confirmed further the proposed electrochemical reaction mechanism. This study probably offers the possibility for preparation an excellent Sudan I sensor. (C) 2016 Elsevier B.V. All rights-reserved.