A stable graphene dispersing system was prepared by using ethanol amine as dispersant and hydrazine hydrate as reductant. UV-vis spectroscopy (UV-vis), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the dispersion and pH-response properties of the system. The results show that the graphene can be modified by ethanol amine to form the composite (ETA-RGO), leading to a stable and uniform graphene dispersion. AFM and TEM show that the maximum width of graphene in the system is about 1 μm, and the thickness is about 0.8nm. In addition, graphene tended to agglomerate when the pH value of the system was decreased to 6. This system can not only disperse graphene in aqueous solution, but also endow graphene with pH-response property. It is expected to extend the application range of graphene related materials in the biological field.