This study was carried out to evaluate the relationship between the biological lead exposure indices and air lead concentrations measured by personal air samplers. The 72 occupationally lead exposed workers were observed and the biological lead exposure indices chosen for this study were blood lead(PuB), urine lead(PbU), zinc protoporphyrin in whole blood(ZPP), gamma-aminolevulinic acid in urine(ALAU), gamma-aminolevulinic acid dehydratase activity(ALAD), coproporphyrin in urine(CPU) and hemoglobin(Hb). The workers were divided into four groups by air lead concentrations: Group I; under 0.05 mg/m3, Group II; 0.05-0.10 mg/m3, Group III; 0.10-0.15 mg/m3 and Group IV; and over 0.15 mg/m3. For evaluation the relationship between the biological lead exposure indices and air lead concentrations was used as correlation coefficients. The results obtained were as follows: 1. In Group I, II, III and IV, the mean value of PbB were 25.45+/-1.84 microgram/dl, 27.87+/-3.53 microgram/dl, 31.21+/-1.76 microgram/dl and 47.02+/-13.96 microgram/dl. Between Group IV and other groups showed statistically significant difference(p<0.05). 2. There was an increasing tendency of PbB, PbU, ALAU and ZPP according to the increase the mean air lead concentration, while ALAD has decreasing tendency. CPU and Hb did not show any constant tendency. 3. Correlation coefficients between PbB, PbU, ZPP, ALAU, ALAD, CPU, Hb and air lead concentration were 0.95, 0.83, 0.89, 0.72, -0.83, 0.51 and -0.45 respectively, and regression coefficient between PbB(Y) and PbA(X) was Y=126.8746X+16.9996(P<0.01).