Abstract: Objective To analyze the dynamic blood lead levels in workers exposed to lead fume and dust in a large-scale enterprise manufacturing lead accumulators during the past 12 years, and evaluate the effect of prevention on occupational lead poisoning. Methods The on-site occupational health investigation was conducted to understand the manufacture process and basic occupational health situation. The lead fume (dust) concentration at workplace were detected by the flame atomic absorption spectrometry (FAAS) and the blood lead level of workers was detected by the graphite furnace atomic absorption spectrometry (GFAAS). The results were evaluated according to GBZ2.1-2007 and GBZ37-2002, respectively. Results The range of time-weighted average concentration of lead dust was 0.002-3.105 mg/m3 and its median was 0.047 mg/m3, the range of qualified rate was 45.0% -83.3%, and the average qualified rate was 61.7% (187/303). While the range of time-weighted average concentration of the lead fume was 0.002-2.523 mg/m3 and its median was 0.039mg/m3, the range of qualified rate was 20.0%-100%, and the average qualified rate was 49.0% (73/149) since the lead accumulator manufacturer put into production (2001-2012). The qualified rates of lead fume and dust were 31.8% -88.9% and the average qualified rate was 57.7% (260/452). The differences of qualified rates in different years were statistically significant (P<0.01). The qualified rate of lead fume (dust) rose from31.8% in 2002 to 88.9% in 2011. A total of 7893 workers had regular occupational health examination in the past 12 years. The range of blood lead concentration was 0.080-4.213 μmol/L and the average was (1.098±0.464)μmol/L. The blood lead content of men (1.131±0.440 μmol/L) was higher than that of women (0.727±0.340 μmol/L) (P<0.01). The mean blood lead levels of workers showed a significant downtrend with the growth of years (R=-0.755, P<0.01). The constituent ratios of different blood lead levels of <1.9, 1.9-2.9, and >2.9 μmol/L in workers were 94.83%, 4.78%, and0.39%, respectively. The concentrations of blood lead in workers were classified as < 1.9 μmol/L (normalrank) and ≥ 1.9 (higherrank) to conduct the Chi-squaretest. The differences between two ranks of blood lead levels in different years were statistically significant (P<0.01). The blood lead level of exposed workers at rank of < 1.9 μmol/L was up to 100.00% in 2012 from 80.99% in 2001. Seven workers were diagnosed with chronic occupational lead poisoning, including 5 mild and 2 moderate cases. Conclusion The concentration of lead fume (dust) and the blood lead level of exposed workers declined year by year since enterprise starting manufacturing the lead accumulators. The exceeding standard rate of blood lead and incidence rate of chronic occupational lead poisoning were low.The effect of prevention on chronic occupational lead poisoning was remarkable.