The adverse health effects of fine particles in the air pollution has been confirmed, and health consequences induced by ultrafine particles (mass media aerodynamic diameter < 0.1 micrometer), which was also known as nanoparticles, was drawing an increasing attention by researchers. Firstly, this review discussed the sources and physicochemical characteristics of nanoparticles in the atmosphere in China. And then we focused on the biological effects and potential toxicity mechanisms of some common nanoparticles in the atmosphere on the major tissues and organs. Finally, the research focus of the nano particles in air pollutants was also presented.