Nanomaterials have unique physicochemical properties compared with those bulk materials of the same composition. Possible undesirable results of these capabilities are harmful interactions with biological systems and the environment, with the potential to generate toxicity. A number of studies on the effects of Nanomaterials in vitro and in vivo systems have been published. However, while the number of nanomaterials types and applications continues to increase, studies to characterize their effects after exposure and to address their potential toxicity are few in comparison, there is still a need for further studies that conclusively establish their safety/toxicity. The establishment of principles and test procedures to ensure safe manufacture and use of nanomaterials in the marketplace is urgently required and achievable. The major goal of this review is to summarize 1) analytical techniques applied for characterization of nanomaterials, 2) current analytical methods to assess nanomaterials toxicity in vitro and in vivo; 3) research progress of polymeric nanomaterials toxicity; 4) outlook.