Facile and stable nanocomposites, carbon nanocages (CNCs)-reduced graphene oxide (RGO), were developed via one-pot in situ solvothermal reaction in this study. Transmission electron microscope, scanning electron microscope, X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, atomic focus microscope, N2 adsorption/desorption isotherms, thermogravimetric analysis and Fourier-transform infrared were performed to characterize the CNCs-RGO hybrid material. The electrochemical detections of catechol (CC) and hydroquinone (HQ) were investigated by means of cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The excellent electrocatalytic activity and reversibility have been shown on the modified electrode toward oxidation of both CC and HQ in 0.04 M acetate buffer solution (pH = 4.0). The relationship between the oxidation peak current of CC and its concentration was linear over the range from 1 to 400 μM in the presence of 100 μM HQ, and the linear relationship between the oxidation peak current of HQ and its concentration can be obtained range from 1 to 300 μM in the presence of 100 μM CC. The detection limits (S/N = 3) for CC and HQ were 0.40 and 0.87 μM, respectively.