Abstract: Even though radiotherapy plays an important role in the treatment of tumors, the problems of toxic and side effects of normal tissues produced by radiotherapy and tumor tolerance to irradiation have not been solved. Gold nanoparticles(GNPs) are a new type of nanoparticle radiosensitizer. As a radiosensitizer, GNPs have become the focus of research because of their high biocompatibility. Their physical and chemical properties(including size, surface charge, and shape) can affect their metabolism behavior and tumor accumulation, thereby resulting in different sensitizing effect of radiotherapy. This review will summarize the progress of recent research on GNPs as a radiosensitizer.