Liquid-crystalline blue phases are stable only for very narrow temperature range between the isotropic and the chiral nematic phase that severely hinders their applicability. Herein, aminoazobenzol group was chemically grafted onto graphene oxide (GO) via amidization reaction. Successful grafting of aminoazobenzol group was confirmed using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), UV-vis absorption spectra and Thermogravimetric analysis (TGA). The resultant aminoazobenzol group modified GO sheets which is reduced (GO-Az) were easily redispersed in common organic solvents. By doping different contents of GO-Az nanosheets could stabilize blue phase and increase the blue phase range. When doped with 0.5wt% GO-Az, the mixtures show the wider range with 5.4 degrees C than the range with 3.6 degrees C of blue phase liquid crystals without GO-Az. Meanwhile, the phase sequence and the range of the aforementioned phases are reproducible upon heating and cooling, which shows that the blue phases doped with GO-Az nanosheets are thermodynamically stable.