Abstract: Objective To study cytogenetic effect of low-dose ionizing radiation among low-dose ionizing radiation exposed workers.Methods Cross-sectional study was used and field radiation dose,individual radiation dose and genetic indicators were monitored in the study.Results The average values of chromosome aberration rate and the detection rate in the case group were higher than those of the control.The average value of micronucleus rate and the detection rate were higher than those of the control with significant differences(P < 0.01 for all).The rates of chromo some aberration and micro nucleus of different yearly dose group and accumulated dose group were significant higher than those of control group(P < 0.01 for all).There was an increasing trend for the rates of chromo some aberration and micronucleus and micronucleus detection with the increase of annual dose or accumulated dose.Conclusion The increases of chromo some abration rate and micronucleus rate of lymphocyte caused by longterm lowdose exposure to ionizing radiation is significantly related to the individual accumulated dose among radiological workers.