Abstract: Graphene oxide is a kind of oxygenated derivative of grapheme, as a new type of carbon nanomaterial, it has various characteristics:high drug loading capacity, high ability of being modified, and unique optical property, thus it shows great application potential in the aspects of drug delivery, bio-imaging, photothermal therapy, and so on. However, with more and more researches of graphene oxide in the biomedical field, its biocompatibility becomes a main obstacle for its clinical application. Therefore, this paper reviews the biocompatibility of graphene oxide in vitro and in vivo, and how its toxicity in vitro and in vivo is influenced by the surface modifier. Through analyzing the influence of such toxicity on cells and animals subjected to studies, which is caused by physicochemical properties of graphene oxide, its dosage, and surface modification, etc., it provides reference for the development of effective and safe new nanocarriers.