Monosuccinyl beta-cyclodextrin (succinyl-beta-CD) was synthesized and the selectivity to quercetin and rutin of the succinyl-beta-CD-modified, multi-wall carbon nanotube (MWNT)-coated, glassy carbon electrode [(succinyl-beta-CD + MWNT)/GCE] was investigated. H-1 NMR and MALDI-MS data confirmed molecular structure of the synthesized succinyl-beta-CD. As a dopant in carboxylated MWNT-modified electrode, succinyl-beta-CD clearly separated the peak potential (E-p) of quercetin from that of rutin. The measured peak potential separation (Delta E-p) was 110 mV. More favorable complexation between succinyl-beta-CD and quercetin may enhance relative selectivity to quercetin of the (succinyl-beta-CD + MWNT)/GCE in quercetin-rutin mixture as compared to the beta-CD-modified GCE.