Nowadays, biodegradable nanoscale preparations such as liposomes, micelles, nanoparticles (NPs), and solid lipid nanoparticles (SLN) have attracted increasing attention from major researchers. Meanwhile the biosafety of the nanomaterials brings more and more attention. Toxicity of the biodegradable nanoscale preparations varies depending on their particle size, shape, surface structure, etc. This article aims to review the toxicity of the above-mentioned nanoscale preparations and the relative methodology. It may be significant for successful use of more nanoscale preparations in clinical practice.