While the nephrotoxicity of high-dose nano-TiO 2 has been demonstrated, very little is known about the mechanism of oxidative stress to the animal kidney. In order to understand the nephrotoxicity of nano-anatase TiO 2 particles, various biochemical and chemical parameters were assayed in mouse kidneys. Abdominal exposures of high-dose nano-anatase TiO 2 caused nephritis and oxidative stress to kidney. An increase in coefficients of the kidney, Ti accumulation and histopathological changes in kidney could be observed, followed by increased reactive oxygen species generation and lipid peroxidation, and decreased activities of superoxide dismutase, catalase, ascorbate peroxidase and total antioxidant capacity as well as antioxidants such as glutathione and ascorbic acid content. In addition, kidney functions were disrupted, including increase of the creatinine, calcium and phosphonium, and reduction of uric acid and blood urea nitrogen. Our results suggest that nephritis generation in mice caused by nano-anatase TiO 2 particles is closely related to oxidative stress.