Abstract: Objective　To investigate the reference intervals of blood cadmium and urine mercury in Jiangsu，Zhejiang，Shanghai and Anhui regions among 18-22-year-old males，and to provide realistic reference standards for firefighter occupational health examination of heavy metal screening.  Methods　The atomic absorption spectrophotometry was used for blood cadmium determination in 1 683 new firefighters. The acidic stannous chloride reduction method was used for the determination of urine mercury，and the results were calibrated by creatinine（Cr）. The blood cadmium and urine mercury values were analyzed statistically. The results were classified and analyzed comparatively according to regions and smoking with reference intervals calculated by P₀-P₉₅.  Results　In Jiangsu，Zhejiang，Shanghai and Anhui regions among 18-22-year-old males，the blood cadmium values were positively skewed distribution，and the reference interval was 0-6.70 μg/L. Urine mercury values were positively skewed distribution，and the reference interval was 0-3.00 μg/g Cr. The regional comparison had no statistical significance（P＞0.05）. The comparison between smoking group and non-smoking group had statistical significance（P＜0.05）.  Conclusions　The reference intervals of blood cadmium and urine mercury should be established and classified between different regions and different ages.

Key words: Blood cadmium, Urine mercury, Reference interval