Abstract: Objective To study the cell proliferation activity and apoptosis level in radiation exposed persons.Methods Choose 80 radiation exposed persons as expermiental group,and 30 radiation unexposed persons as normal grop.The cell proliferation and expression levels of proliferative cell nuclear antigen(PCNA),Bc l 2,B ax prote in were detected.Results The cell prolife ration activity,PCNA,Bc l 2 expression were 0.83±0.06,53.97±7.75,21.53±5.19,respectively in the experimental group and lower than those of in the normal group(0.90±0.07,60.37±7.75,25.72±5.21).But the Bax expression(31.69±5.68)was higher than that of in the normal group(26.38±5.55).All the differences were statistically significant(P<0.05).Conclusion Radiation exposure has certa in effects on the cell proliferation and apoptosis level in radiation exposed person.