ＤＮＡ分子是生物细胞中易受辐射损伤的敏感分子或称靶分子。α射线、Ｘ射线、γ射线、紫外线等辐射因子对ＤＮＡ结构造成的任何改变都可能导致细胞突变、癌变甚至死亡。电离辐射诱发ＤＮＡ损伤主要有碱基损伤、单链断裂（ｓｓｂ）、双断裂（ｄｓｂ）等。同时生物体内本身存在着修复体系。近年来，随着分子生物学的深入发展及新技术的应用．ＤＮＡ损伤、修复及突变的研究已取得了很大进展。 DNA molecules are sensitive molecules or target molecules in biological cells that are vulnerable to radiation. Any changes to the DNA structure caused by alpha radiation, X-rays, gamma rays, ultraviolet radiation and other radiation factors can lead to cell mutation, carcinogenesis and even death. Ionizing radiation-induced DNA damage are mainly base damage, single-strand break (ssb), double-break (dsb) and the like. At the same time there is a biological system itself repair system. In recent years, with the further development of molecular biology and the application of new technologies. Research on DNA damage, repair and mutation has made great progress.