Analyses of lead and zinc were made by means of standard addition method using atomic absorption spectrophotometer(Baird Ltd., Model A5100) with flameless method for lead and flame method for zinc. The blood samples used were merely diluted with triton x-100, because it was simple, rapid and minimal risk of contamination. Mean recovery rate for lead added to the blood ranged from 97.7 to 101.3% with coefficient of variation ranging from 1.9 to 10.7%, and that for the added zinc ranged from 99.0 to 102.2% with coefficient of variation ranging from 2.1 to 9.1%. In repeated measurements of zinc in the blood, good reproducibility and interindividual variation were proved(p<0.01). In comparison of the lead and zinc concentrations in the blood determined by the standard addition method and standard method, there were good correlations between 2 sets of data (r=0.9731 for lead and r=0.9785 for zinc), although lead levels were estimated higher by the former method(p<0.01) and zinc levels by the latter method(p<0.01). It can be concluded that lead and zinc levels in blood standard addition method is reliable for determination of lead and zinc in the blood with good accuracy and reproducibility.