Abstract： Objective To explore the long-term health effects of overexpose to radiation.Methods The 32 -41-year medical followed-up observations were performed for 25 persons exposed to ionizing radiation in the dose range of 0.10 -0.33 Gy. Observations were made of clinical symptom,eye lens,cytogenetics,immune function and endocrine function for these persons. Results The incidence of neurasthenic symptom was higher in exposed group than that in control group.2 cases suffered from liver cancer and esophageal cancer,respectively. Posterior capsule punctate phacoscotasmus of the lens wereobserved in 7 cases.There was I case of cataract in the exposed group. The frequencies of chromosomeaberration and micronucleis in peripheral blood lymphocyte in the exposed group were significantly higherthan those in control group (x2 =8.88,8.71,40.60,45.63,P ＜ 0.05 ).The average value of serum IgG was higher(t =2.16,P ＜0.05 ),while that of IgM was obviously lower in the exposed group (t =2.03,P ＜0.05).The average values of serum triiodothyronine (T3),thyroxine (T4 ) and thyroid-stimulating hormone (TSH) in the exposed group were obviously lower than those in the control group (t =2.40,3.54,2.13,P ＜0.05 ).Conclusions Overexposure has effect on lens,immune function,cytogenetics to some degree.It is important to observe the long-term health effect on overexposed persons.