Abstract: Low dose radiation (LDR) can induce adaptive response in vivo and cultured cells.This phenomenon has been confirmed for more than 10 years. After the discovery, numerous research works on its intrinsic mechanism have been carried out. It was reported that the adaptive response is related to many factors. These factors include the DNA repair system induced by LDR,the function of genes and proteins induced by LDR,the function of antioxidant enzyme,cel-luar signal transduction and cell-cycle delay relation to p53 and so on.