Objective: To explore the effects of X-ray repair cross complementing gene 1 (XRCC1) polymorphism and low dose ionizing radiation exposure on radiology professionals’ peripheral blood lymphocyte micronucleus. Methods: A matched case-control study was designed. From 2013 to 2015, 1 102 radiology professionals with micronucleus test rusults, and 45 cases with present micronucleus were enroled into case group. 180 diagnostic radiology technicians detecting no micronucleus were chosen as control group, cases and controls were 1∶4 mached on gender, age ≤40 or >40 years old. According to the detection of micronucleus levels (0‰, 1‰, 2‰) , the objects of our study were divided into the reference group, the low detection group and the medium detection group. The form of radiation workers’ occupational health examination was used to collect the general baseline of the research objects, history of smoking, drinking, poisonous and harmful material exposure, past medical history, accumulated illuminated dose and lymphocyte micronucleus rates (‰) , etc. Using restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) technology for genotyping; Compared the baseline data and radiation exposure level between the differentmicrokernel detection groups; Adopted multivariate logistic regression to analysis the combination effect of XRCC1 Arg399Gln gene polymorphism and accumulated illuminated dosefor micronucleus rate. Results: The accumulated illuminated dose in the reference group, the low detection group and the medium detection group were (23.44±15.23) , (21.76±2.56) , (24.22±18.61) mSv, respectively. There was no statistically significant difference among the groups (P>0.05) . Under the dominant inheritance mode, after adjusted age, smoking and drinking factors, the results suggested that XRCC1 Arg399Gln micronucleus medium detection group compared with the reference group, Arg399Gln-GG as reference, Arg399Gln-GA+AA decreased the occurrence of micronucleus (OR=0.175, 95%CI: 0.036-0.848) . Arg194Trp and Arg280His did not affect the incidence of micronucleus (P>0.05) . Did not find the combination effect of XRCC1 Arg399Gln gene polymorphism and accumulated illuminated dose for micronucleus rate (P>0.05) . Conclusion XRCC1 Arg399Gln gene polymorphism can affect the incidence of micronucleus, and carrying the XRCC1 Arg399Gln-GA+AA genotype is a protective factor of micronucleus’s occurrence, but low dose ionizing radiation may not affect the occurrence of micronucleus independently.