A β-cyclodextrin functionalized graphene modified glassy carbon electrode(β-CD-GR/GCE) was prepared by drop-coating method.The electrochemical behaviors of o-nitrophenol(o-NP) and p-nitrophenol(p-NP) on the modified electrode were investigated by cyclic voltammetry and second-order derivative linear sweep voltammetry.The β-CD-GR/GCE showed an excellent electrocatalytical effect on the reduction of p-NP and o-NP.Besides,high resolution capacity to p-NP and o-NP was obtained.Under the optimized conditions,second-order derivative linear sweep voltammetry was utilized for the determination of p-NP and o-NP.There were good linearities for o-NP and p-NP in the concentration ranges of 0.2-10 μmol/L and 0.06-10 μmol/L with detection limits(S/N=3) of 0.08 μmol/L and 0.02 μmol/L,respectively.The proposed method could be applied in the simultaneous determination of o-NP and p-NP in environmental water samples with rapidness and accuracy.