Graphene has been highlighted as an additive material to ameliorate functions of biomaterials due to its unique structure and superelasticity. In this study, graphene at different concentration (up to 10%) was incorporated into a hybrid membrane composed of chitosan and silica xerogel to enhance the functionality of the hybrid membrane for guided bone regeneration (GBR) through in situ sol-gel technique. The effect of graphene incorporation was evaluated in terms of morphology, mechanical property, and biological property. In SEM observation, graphene (G)-incorporated membranes showed macroporous structure and nanofibrous microstructure which could allow protein to attach onto membrane more efficiently. The hybrid membrane containing 10% graphene was found to have highly porous and nanofibrous structure with the highest level of protein adsorption. These G-incorporated membranes also showed improved mechanical properties compared to hybrid membrane only (control) in wet state. However, the tensile strength and elongation were decreased when 10% graphene was incorporated into the hybrid membrane. Both in vitro and in vivo tests confirmed that G-incorporated membranes had similar biological properties to those of osteogenic hybrid membrane with excellent GBR ability. These findings demonstrate that proper amount of graphene could be added to hybrid membrane to increase loading capacity of biomolecules for guided bone regeneration.