The purpose of this study is to establish hematological values in healthy workers. Seven thousand one hundred industrial workers, of which 4, 080 were male and 3, 020 were female, were investigated as to red blood cell count, hemoglobin content, hematocrit value and mean corpuscular constants (mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration). Frequency distributions of six sorts of hematological values in men were close to the normal. But different from those in men frequency distribution curves were skew and shifted to the left side in women. These tendencies of mean corpuscular constants were larger than those of red blood cell count, hemoglobin content and hematocrit value. The means and the standard deviations (and 5th-95th percentile) were 487.3±34.7 (430-544)×104/mm3 for red blood cell count in men, 421.6±31.1 (370-473)×104/mm3 for red blood cell count in women, 15.1±1.0 (13.3-16.8) g/dl for hemoglobin content in men, 12.4±1.1 (10.7-14.2) g/dl for hemoglobin content in women, 46.1±3.0 (41-51) % for hematocrit value in men, 38.5±3.0 (33-43) % for hematocrit value in women, 94.8±4.8 (87-103) μm3 for mean corpuscular volume in men, 91.1±6.0 (81-101) μm3 for mean corpuscular volume in women, 30.5±1.5 (28-33) μg for mean corpuscular hemoglobin in men, 29.2±2.1 (26-33) μg for mean corpuscular hemoglobin in women, 32.3±0.8 (31-34) % for mean corpuscular hemoglobin concentration in men and 32.1±0.9 (31-34) % for mean corpuscular hemoglobin concentration in women. Among the means of hematological values, red blood cell count and hemoglobin content in both men and women and hematocrit value in men tended to decline with age, but mean corpuscular volume and mean corpuscular hemoglobin in both men and women tended to increase with age. These differences by age were statistically significant. The sex differences of the means of all were statistically significant. The sex differences of the means of red blood cell count, hemoglobin content, and hematocrit value were larger than those of mean corpuscular constants.