Abstract: AIMTo study the host-guest inclusion behavior of anticancer drug irisquinone with β-cyclodextrin. METHODSThe variance of the reduction ware of irisquinone in the absence and presence of β-cyclodextrin was examined by cyclic voltammetry at the hanging mercury drop electrode. RESULTSIn 0.04 mol·L^-1 KH₂PO₄-Na₂HPO₄ (pH 6.8) supporting electrolyte which was close to physiological condition, the introduction of β-cyclodextrin resulted in both decrease of reduction current and the positive shift of peak potential of reduction ware of irisquinone. CONCLUSIONThe electroactive guest molecule irisquinone was complexed with host molecule β-cyclodextrin to the formation of 1∶1 inclusion complex. The inclusion constant K_f was 1.92×10³ L·mol^-1 by the electric current method. The formation of the inclusion complex enhanced the stability of irisquinone.