Abstract The electrochemical properties of two basic violets (methyl violet and ethyl violet) at the MWNTs/Nafion modified glassy carbon electrode were investigated. The redox of the basic violets is two-electron and two-proton process, and methyl violet presents stronger electron transfer capacity than ethyl violet. Meanwhile, the inclusion constants of the two basic violets with five CDs were determined by differential pulse voltammetry (DPV). The two basic violets and CDs can form 1:1 complexes, The inclusion capacities of the two basic violets follow the same order: CM-β-CD 〉 HP-β-CD 〉 TM-β-CD 〉 DM-β- CD 〉 β-CD. ?2009 Yu Jing Guo. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.