Abstract: Ionizing radiations produce deleterious effect in the living organisms and the population of human becoming exposed to radiation environment (e.g. space exploration, radiotherapy and nuclear medicine) is rapidly increasing. The development of radioprotective agents has been the subject of intense research. However, to date, no ideal radioprotectors are available as most synthetic compounds are toxic and have limited use in clinical practice. Natural compounds are widely used in traditional systems of medicine, and which have been evaluated as significant radioprotectors. This article reviewed some of the most promising natural compounds, such as polyphenols, flavonoids, anthocyanins, polysaccharides, and melatonin and they seemed to exert their effect through antioxidant activity, lipid peroxidation inhibition, increase of antioxidant enzymes, inhibition of DNA damage and so on.