Abstract: Cerium oxide nanoparticles (CeO₂ NPs), as the oxides of the most abundant elements in rare earths, have been widely used in biomedical and industrial production and other fields that are closely related to human life. China is a large country in resources and production of rare earth, and the impact of CeO₂ NPs on human health has been increasingly concerned. In response to the possible health risks of CeO₂ NPs, researchers begin to focus on their toxic effects on living organisms, especially on the reproductive system. The male reproductive system is not only responsible for producing sperm and regulating the secretion of testosterone, but also plays a key role in maintaining male sexual characters and function. Any adverse effects on the male reproductive system may lead to reduced fertility and reproductive dysfunction. Some studies have shown that long-term exposure to CeO₂ NPs may lead to gonadal damage, sex hormone disorders, and other problems in male animals. Therefore, an in-depth study of the potential effects of CeO₂ NPs on the male reproductive system is of great scientific significance and practical value. In this study, we reviewed the male reproductive toxicity of CeO₂ NPs in terms of spermatogenic cells, spermatozoa structure, blood-testis barrier, hypothalamic-pituitary-gonadal axis, and functional changes in epididymis, and analyzed the effects of the size and shape of physicochemical parameters of CeO₂ NPs on the toxicity to male reproductive system. The findings will provide a theoretical basis and scientific evidence for the rational use of CeO₂ NPs.