| Graphene, a kind of widely used emerging non-metallic nanomaterials, has unique electrical and mechanical properties, large specific surface area and the potential biological compatibility, and has been widely applied in materials, electronics, energy, optical and biomedical and other fields. Meanwhile the environmental behavior and biological toxicity of grapheme have gradually aroused the attention. This article summarized the related research about animal toxicity, cytotoxicity, toxicity influence factors and the toxicity mechanisms of graphene nanomaterials. From the review, we can draw the following conclusions: graphene nano materials can enter into the body through intratracheal instillation, inhalation, intravenous injection, intraperitoneal injection and oral administration, then reach the lung, liver, spleen, and other locations through mechanical barrier, blood-brain barrier and blood-placental barrier, and ultimately cause acute or chronic injury. The possible toxicity mechanisms of graphene mainly focused on oxidative stress, mitochondrial damage, DNA damage, inflammatory and apoptosis. The different physicochemical characteristics of graphene, including its concentration, size, surface structure and functional groups strongly influence its toxicity in biological systems. Finally, we point out the limitation of this article and propose the prospected development direction of biological toxicity research on graphene nanomaterials. This review provides theoretical guidance for the safe application of graphene materials.