Abstract: Nanobiology, nanomedicine, and naontoxicology are newly developed interdisciplinary research fields accompanied by the development of nanotechnology. Quantitative determination of nanomaterials in vivo is the common problem that is experienced by these disciplines. Radiotracer techniques had the advantage of high sensitivity, good accuracy, simplicity and low interference. This review describes radiolabeling methods of 6 important metallic and metal oxide nanomaterials, such as gold, silver, iron oxide, titanium oxide, and zinc oxide nanoparticles. Advantage, disadvantage, and caution of each method are summarized.