In order to measure serum copper concentration, 163 adult males working at different units of copper plant from a total population of 671, were selected by simple random sampling. Eighty three subjects working at melting foundry, 49 in extrugen- rolling and 31 at administrative service untils. Eighty four adult male natives of Kerman and it's suburbs were randomly choosen as control group, serum copper concentration was determined from measuring serum ceruloplasmin concentration by spectrophotometric method. The mean serum copper concentrations in all three groups u under studies were significantly higher than controls ( p<0.05). The high level of serum copper in administrative, service group who were not derictly involved in copper works compare to other groups may be the results of two events: 1) lower excretion rate of copper via sweat as a result of cooler work environment and 2) absorbing less zinc oxide vapour( compared with the other two groups) due to interference with copper absorption.