Abstract: Objective To study the association betwen XPD751 and XPD312 locus gene polymorphisms and suscepbility to radiation-induced damage,and to provide reliable biomarkers for evaluating ionizing radiation-induced damage and screening the high-risk group exposed to ionizing radiation.Methods All the subjects were recruited from workers exposed to radiation in Tangshan city,182 with chromosomal aberrations were selected as cases and the control group without radiation-induced damage,moreover the case group matched the control group according to 1B1.Chromosome analysis with the micro amount of full blood sample cultivation.PCR-RFLP was used to examine the genotype of two XPD loci(751 and 312).Results Statistical difference was found between the fr equencies of XPD751 AA(wild type)and the mutant gene type including heterozygote AC and homozygote CC(OR=1.90,95%CI=1.10~3.28,P<0.05).The wild gene type in case group was statistically higher than that in the control groups.No statistcal difference was found between the frequencies of XPD312 CA(wild type) and the mutant gene type including heterozygote GC and homozygote AA(P>0.05).Conclusion XPD 751 polymorphism is associated with ionizing radiation-induced chromosomal damage,and AA genotype in XPD751 is possible risk factor of radiation-induced chromosomal damege.